The invention relates to the field of bearing test equipment, in particular to a simple main shaft connection mechanism of a high-speed bearing tester. The main shaft connection mechanism comprises atesting head main shaft and a tester main shaft which are coaxial and oppositely distributed, wherein a plurality of first connecting holes are formed in the end face of the testing head main shaft, aplurality of second connecting holes are formed in the end face of the tester main shaft, and the number of the second connecting holes is the same as that of the first connecting holes; and the positions of the second connecting holes are in one-to-one correspondence with those of the first connecting holes, and a buffer connecting rod is inserted into any set of first connecting hole and secondconnecting hole corresponding to each other. According to the simple main shaft connection mechanism, the noise at the main shaft joint of the high-speed bearing tester can be remarkably reduced, thecost is low, and the connection is simple and rapid.