The utility model relates to a speed change mechanism of a motor, which comprises a shell II, a
swash plate II and a
plunger hole are arranged in the shell II, a spring and a speed regulation
plunger are arranged in the
plunger hole, the speed regulation plunger is of a cylinder structure, a spherical surface is arranged at one end of the speed regulation plunger and abuts against the
swash plate II, a cavity is arranged at the other end of the speed regulation plunger, one end of the spring is positioned in the cavity, and the other end of the spring is positioned in the cavity. The other end abuts against the bottom wall of the plunger hole. By arranging the spring, the speed regulating plunger is always in contact with the
swash plate II, and the contact points are kept consistent, so that the swash plate II is prevented from being impacted during high and
low speed switching, and the service life of the swash plate II is prolonged; the speed regulation plunger is of a cylinder structure, the fit clearance between the speed regulation plunger and the plunger hole is small, the leakage amount is small, and the
motor efficiency is hardly influenced, so that a sealing ring does not need to be installed on the speed regulation plunger, and the problem that the coaxiality of the upper size and the lower size of a sealing groove in a conical plunger in the prior art is not easy to control is solved; the motion stability is effectively improved, the product structure is simplified, and the production cost is reduced.