The invention relates to a combined testing machine for detecting an insulating cylinder, comprising a frame, wherein an axial loading device for supplying load to an axial anti-pulling and anti-pressuring test of the insulating cylinder is arranged between left and right sides of the frame; and a radial loading device for supplying the load to an anti-bending test of the insulating cylinder is arranged between front and back sides of the frame. As the combined testing machine for detecting the insulating cylinder provided by the invention integrates the axial loading device with the radial loading device on the same frame, the anti-pulling test, the anti-pressuring test and the anti-bending test to the insulating cylinder can be performed by only clamping once without separating the anti-pulling test, the anti-pressuring test and the anti-bending test of the insulating cylinder, which reduces the test clamping times of the insulating cylinder, and improves the testing efficiency.