The invention discloses a portable transmitter calibrator, comprising a voltage stabilizing transformer, an alternating-current constant voltage and constant current module, a program controlled resistor module, a DSP (Digital Signal Processor) controller and a human-computer interface, wherein the alternating-current constant voltage and constant current module comprises a rectifying circuit, an inverter, a filter and a sampling adjustment circuit; the inverter comprises an intelligent power module and a photoelectric isolating drive circuit; the voltage stabilizing transformer is connected with a transmitter to be calibrated; the output end of the sampling adjustment circuit is connected with the DSP controller; the program controlled resistor module is separately connected with the DSP controller and the transmitter to be calibrated; and the human-computer interface is connected with the DSP controller. The portable transmitter calibrator can realize convenient calibration for multiple transmitters, has the characteristics of multiple functions, small size, light mass, portability and the like, and can significantly improve the convenience of transmitter calibration and save money.