An electric pulse-controlled thermal spin injector is theoretically proposed, which consists of a junction with a single-molecule magnet sandwiched between the ferromagnetic and nonmagnetic leads. By applying a temperature gradient and a time-varying bias pulses across the junction, the spin direction of the single-molecule magnet can be controlled to be antiparallel or parallel to the magnetization of the ferromagnetic lead by a spin-transfer torque effect, and the spin polarization of thermoelectric current tunneling through this junction can...