The invention discloses a soldering flux spraying device of an automatic wave furnace soldering machine, comprising a transmission arm, a sensor bracket, a sensor fixing arm, a sensor, a solenoid valve, a flow meter, a shower nozzle, a slide rail, a sensing framework, a sensing template, a non-glare template and a motor, wherein the sensing framework is provided with more than one window, and the sensing template is arranged in the window; the sensing template selects a region which does not need to be sprayed according to requirements to form openings with corresponding sizes and positions in the positions according to a circuit board needing to be produced; a light sensor sensing principle is utilized to enable the sensor to send a signal to control the solenoid valve to be conducted when the sensing template moves to a reflecting matter; if the sensing template moves to the openings of the template, the sensor does not sense reflection lights because a black non-glare material is arranged above the openings of the template, so as to not send the signal to stop the solenoid valve; no soldering flux is sprayed out of the shower nozzle so as to realize the accurate control; and the material of a control template is selected from paper, and the manufacturing method is simple and feasible.