Thick film circuit capable of prolonging service life of optocoupler

The invention provides a thick film circuit capable of prolonging the service life of an optocoupler. The thick film circuit comprises a DC/DC converter, a multivibrator, a coupling capacitor C1, a monostable circuit SS1, a photoelectric coupler, a coupling capacitor C2, a monostable circuit SS2 and a filter capacitor C3 which are electrically connected in sequence. The input end of the DC/DC converter is connected with the output end of the switch, and the DC/DC converter is used for converting the working voltage into control voltage and outputting the control voltage to the multivibrator; a continuous signal is converted into a pulse signal through the multivibrator, and the duty ratio of a pulse voltage signal is adjusted through the coupling capacitor and the monostable circuit, so that the photoelectric coupler is in a narrow pulse conduction working mode, the conduction time of the photoelectric coupler is greatly shortened, and the service life of the photoelectric coupler is greatly prolonged; and th