To meet the requirements of complex electromagnetic environment, and overcome the high false alarm rate caused by strong background light interference, a laser warming circuit was designed which had strong feature in anti electromagnetic interference and low power consumption. The characteristics and the insufficiency of various existing technologies of laser detection were analyzed. Combined the analog circuit and digital circuit together, the detectable incoming laser wavelength was extended in the analog circuit part, achieving the improvements that the false alarm rates was lower than before according to the digital circuit part based on CPLD.Using high sensitivity and wide band photo detector as the incoming laser receiver could detect different wavelengths of incoming laser signal in the response band of the photo detector. Logic drive circuit based on CPLD could distinguish the pulse width of the incoming light under the rules according to the procedures to eliminate false decision caused by other optical signal and reduce false alarm rate as a result. Testing results in practice showed that the circuit could achieve the targets as follow: amplifier gain G=30, SNR=20 dB, detection range≤5 km, detection wavelength range: 850~1 700 nm,the false alarm rate≤5%.