Single-photon counting is the most sensitive weak light measurement technique , with widespreadapplications in biomedicine , basie physies researeh , making it an important experimental subjeet for the trainingof undergraduates in nuclear physies, nuclear technology, ete, ln practical applications, to reduce noiseinterference and extract time-correlated information, the coincidence method has been widely used in photoncounting technology .However , there is no coincidence-based photon counting teaching experiment equipment atpresent.In particular, the traditional photon counting teaching experiment equipment needs to be matched with a discriminator and coincidenee module , which inereases the cost and complexity of the experimental teaching.[herefore , in order to strengthen the understanding of photon counting measurement and coincidence principlea coincidence-based photon counter was developed based on Field-Programmable Gate Array ( FPGA ).Thecoincidence-pased photoncounterinstrument ,based on the traditional photon counting instrument, hasadded the function of dual-channelphoton coincidence measurement(countingandtmeinterva) and improved the light souree to a pulsed light souree modulated by transistor-transistor logie(TTL) signal through afilter,This makes the instrument not only meet the needs of traditional teaching experiment instruments , but alsoallows various expandable experiments to be designed based on the instrument.