In view of the influence of cloud environment on the ranging accuracy of pulsed laser short-range detection system, the characteristics of laser cloud interference echo signal are analysed. A variable step-size filtering algorithm with step-size memory effect is proposed based on the principle of LMS adaptive filtering to characterise laser cloud echo interference signals. To verify the anti-jamming performance of the proposed filtering method, we analyse three factors of random jamming, pulse width, peak intensity, and echo time interval. A comparative experiment of pulsed laser cloud environment interference filtering is conducted. The results show that the proposed adaptive filtering algorithm can effectively target random parameter cloud interference signals and improve the working stability of pulsed laser short-range detection systems in a cloud environment.