The invention relates to a railway vehicle bogie hanging natural vibration characteristic detection equipment, in particular to a semi-vehicle mass simulation state based bogie hanging natural vibration characteristic test bed. The test bed is mainly composed of a test bed positioning and auxiliary supporting device, a test bed excitation loading device and a semi-vehicle mass simulation loading device; wherein the test bed positioning and auxiliary supporting device is fixedly connected onto a test bed concrete foundation, the test bed excitation loading device is fixedly connected with a construction member on the test bed positioning and auxiliary supporting device, the semi-vehicle mass simulation loading device is connected with the swing bolster or air spring of a bogie to be tested and is fixedly connected with the construction member on the test bed positioning and auxiliary supporting device, the test bed can utilize a mass block to load the bogie, so as to achieve the aim of simulating semi-vehicle mass; and an electro-hydraulic servo system cooperatively controls actuators in different directions, so as to excite the bogie to be tested, thus meeting the requirement of natural vibration frequency test in bogie frame transverse, yawing, nodding and side rolling vibration modes.