diff --git a/mmcv/ops/csrc/pytorch/npu/knn_npu.cpp b/mmcv/ops/csrc/pytorch/npu/knn_npu.cpp
new file mode 100644
index 0000000000..c4a1bcbd25
--- /dev/null
+++ b/mmcv/ops/csrc/pytorch/npu/knn_npu.cpp
@@ -0,0 +1,21 @@
+#include "pytorch_npu_helper.hpp"
+#include "torch_npu/csrc/aten/NPUNativeFunctions.h"
+#include "torch_npu/csrc/framework/utils/OpAdapter.h"
+
+using namespace NPU_NAME_SPACE;
+using namespace std;
+
+void knn_forward_npu(int b, int n, int m, int nsample, const Tensor xyz,
+                     const Tensor new_xyz, Tensor idx, Tensor dist2) {
+  // transpose known from [B, N, 3] to [B, 3, N]
+  at::Tensor source = xyz.transpose(2, 1).contiguous();
+  at::Tensor target = new_xyz.contiguous();
+
+  bool is_from_knn = true;
+  EXEC_NPU_CMD(aclnnKnn, source, target, is_from_knn, dist2);
+}
+
+void knn_forward_impl(int b, int n, int m, int nsample, const Tensor xyz,
+                      const Tensor new_xyz, Tensor idx, Tensor dist2);
+
+REGISTER_NPU_IMPL(knn_forward_impl, knn_forward_npu);
diff --git a/mmcv/ops/csrc/pytorch/npu/three_nn_npu.cpp b/mmcv/ops/csrc/pytorch/npu/three_nn_npu.cpp
new file mode 100644
index 0000000000..6740a731bc
--- /dev/null
+++ b/mmcv/ops/csrc/pytorch/npu/three_nn_npu.cpp
@@ -0,0 +1,20 @@
+#include "pytorch_npu_helper.hpp"
+#include "torch_npu/csrc/aten/NPUNativeFunctions.h"
+#include "torch_npu/csrc/framework/utils/OpAdapter.h"
+
+using namespace NPU_NAME_SPACE;
+using namespace std;
+
+void three_nn_forward_npu(int b, int n, int m, const Tensor unknown,
+                          const Tensor known, Tensor dist2, Tensor idx) {
+  at::Tensor source = known.contiguous();
+  at::Tensor target = unknown.contiguous();
+
+  bool is_from_knn = false;
+  EXEC_NPU_CMD(aclnnKnn, source, target, is_from_knn, dist2);
+}
+
+void three_nn_forward_impl(int b, int n, int m, const Tensor unknown,
+                           const Tensor known, Tensor dist2, Tensor idx);
+
+REGISTER_NPU_IMPL(three_nn_forward_impl, three_nn_forward_npu);
diff --git a/mmcv/ops/knn.py b/mmcv/ops/knn.py
index 48ce92f925..1e2a68d1d2 100644
--- a/mmcv/ops/knn.py
+++ b/mmcv/ops/knn.py
@@ -55,12 +55,31 @@ def forward(ctx,
         center_xyz_device = center_xyz.get_device()
         assert center_xyz_device == xyz.get_device(), \
             'center_xyz and xyz should be put on the same device'
-        if torch.cuda.current_device() != center_xyz_device:
-            torch.cuda.set_device(center_xyz_device)
+        if xyz.device.type != 'npu':
+            if torch.cuda.current_device() != center_xyz_device:
+                torch.cuda.set_device(center_xyz_device)
 
         B, npoint, _ = center_xyz.shape
         N = xyz.shape[1]
 
+        if xyz.device.type == 'npu':
+            dist = center_xyz.new_zeros((B, npoint, N)).float()
+            ext_module.knn_forward(
+                xyz,
+                center_xyz,
+                torch.Tensor([]).npu(),
+                dist,
+                b=B,
+                n=N,
+                m=npoint,
+                nsample=k)
+            dist2, idx = torch.topk(dist, k, dim=2, largest=False, sorted=True)
+            zeros_idx = torch.zeros(
+                xyz.shape[0], center_xyz.shape[1], k, dtype=torch.int32).npu()
+            idx.where(dist2 >= 1e10, zeros_idx)
+            idx = idx.transpose(2, 1).contiguous()  # [B, k, npoint]
+            return idx.int()
+
         idx = center_xyz.new_zeros((B, npoint, k)).int()
         dist2 = center_xyz.new_zeros((B, npoint, k)).float()
 
diff --git a/mmcv/ops/three_nn.py b/mmcv/ops/three_nn.py
index d41b9789cf..52d504609a 100644
--- a/mmcv/ops/three_nn.py
+++ b/mmcv/ops/three_nn.py
@@ -34,6 +34,21 @@ def forward(ctx: Any, target: torch.Tensor,
 
         B, N, _ = target.size()
         m = source.size(1)
+        if source.device.type == 'npu':
+            # strict to fp32
+            source = source.transpose(2, 1).contiguous()
+            dtype_ = source.dtype
+            if dtype_ == torch.float16:
+                target = target.float()
+                source = source.float()
+            dist = target.new_empty(B, N, m)
+            ext_module.three_nn_forward(
+                target, source, dist, torch.Tensor([]).npu(), b=B, n=N, m=m)
+            dist2, idx = torch.topk(dist, 3, dim=2, largest=False, sorted=True)
+            dist2 = torch.sqrt(dist2)
+            if dtype_ == torch.float16:
+                dist2 = dist2.half()
+            return dist2, idx.int()
         dist2 = target.new_empty(B, N, 3)
         idx = target.new_empty(B, N, 3, dtype=torch.int32)