The utility model discloses a low-center high-increased safety type low-speed synchronous motor, which comprises a motor base and a cooler, a stator core and a motor rotor are arranged in the motor base, a winding coil is arranged on the stator core, and two ends of the winding coil are respectively provided with a wind shield; the machine base is provided with a shaft extension end cover and an excitation end cover. a first bearing seat is arranged on the shaft extension end cover; the excitation end cover is provided with a second bearing seat, the motor rotor comprises a rotating shaft anda rotor core, one end of the rotor core is provided with a fan, the section, between the rotor core and the excitation end cover, of the rotating shaft is sequentially and coaxially provided with a resistance disc, a rotating rectification disc and an alternating-current exciter, and the first bearing seat and the second bearing seat are each internally provided with an air-water cooling pipeline.According to the low-center-height high-capacity box-type increased-safety low-speed synchronous motor, cold air firstly passes through the alternating-current exciter, the rectification module and the resistance disc, the surface temperature is relatively low, the service life of electrical elements such as diodes and silicon controlled rectifiers can be prolonged, and the operation reliabilityis improved.