The important role of single-photon detector for laser ceilometers is briefly introduced. On the basis of the basic working principle of single-photon detector (single-photon avalanche diode, SPAD), a passive suppression circuit of SPAD is built. The experiment shows that the dead time of SPAD is above 2 μs, only applicable to the occasion when single-photon counting rate is less than 500 kHz. In order to shorten the dead time of the single-photon detector, improve single-photon counting rate, the mixed suppression circuit of avalanche passive quenching and voltage active recovery is designed. Through the precise timing control, the dead time of the detector is shortened to 100 ns, single-photon counting rate up to 10 MHz. In theory, the spatial resolution of the laser ceilometer can be up to 15 m, mixed quenching circuit of single-photon detector SPAD for the performance of laser ceilometer and smooth development has important significance.