#新节点
conv1_node = onnx.helper.make_node(
    name="Conv_40",  # Name is optional.
    op_type="Conv",
    # Must follow the order of input and output definitions.
    # https://github.com/onnx/onnx/blob/rel-1.9.0/docs/Operators.md#inputs-2---3
    inputs=["input", "backbone.patch_embed.proj.weight", "backbone.patch_embed.proj.bias"],
    outputs=["268"],
    # The following arguments are attributes.
    kernel_shape=[4,4,4],
    strides=[4,4,4],
    dilations=[4,4,4],
    group=1,
    pads=[0,0,0,0,0,0]
)


onnx_model = onnx.load(onnxfile)
graph = onnx_model.graph
graph.node.remove(node)
graph.node.insert(584, conv1_node)
onnx.checker.check_model(onnx_model)
onnx.save(onnx_model, onnxfile)

参考文章：
https://leimao.github.io/blog/ONNX-Python-API/
https://github.com/onnx/onnx/issues/2259