A programmable laser trigger device and the method for controlling the same are disclosed. The programmable laser trigger device comprises: an external signal module and a command executing module. The external signal module is capable of interfacing the inputs and outputs of waveform command and signals. The command executing module further comprises: a waveform command memory, for storing the waveform command; a waveform command decoder; a waveform generator; and a buffer memory, acting as a waveform trigger parameter buffer between the waveform command decoder and the waveform generator; wherein the waveform command decoder accesses the waveform command stored in the memory for pre-decoding an executing code while generating a sequence of waveform trigger parameters to be stored in the buffer memory, which provides the waveform generator with the sequence of waveform trigger parameters to be transformed into a pulse-width modulation (PWM) pulse train. With the aforesaid device and method, not only unequal pulse outputs can be generated with good flexibility for matching the needs of various manufacturing processes, but also through the instructions to an external feedback signal from the waveform command, the laser pulses outputted therefrom can be modulated in real time in response to the external feedback signal.