The invention relates to a digital developing equipment adopting laser exposure, especially a laser direct modulation apparatus used for digital developing equipment, The apparatus is characterized inthat: it comprises a spectroscope cooperating with a laser to split a light beam into two branches, and a photoelectric conversion module cooperated with the light branch used for high speed sampling; the output terminal of the photoelectric conversion module is in electric connection with the input terminal of an amplification circuit; the output terminal of the amplification circuit is connected with the input terminal of a comparison circuit; the other end of the comparison circuit is connected with reference signal; and the output terminal of the comparison circuit is in electric connection with a power control circuit, thereby, the output power of the laser can be controlled by the sampling signal. The invention can guarantee that the output power of laser is normal in working state,and is lowest in standby state; therefore, prolongs the service life of the laser greatly; and has a simple structure and low cost.