To focus on low drift of sea ice and to meet the accuracy requirement of radar monitoring system, a video accumulation and optimized mean filtering algorithm is proposed to detect sea ice concentration by data filtering in both time and space dimensions. The deconvolution algorithm is adopted for radar echo processing, which can reduce the angular error due to the horizontal beam width (θH) and the radial error due to the radar pulse width (τ) effectively. Based on the statistical characteristics of noise, simulation is used to verify the performance of video accumulation and optimized mean filtering algorithm on the Signal-to-Noise Rate (SNR) of sea ice echo images. Taking the measured data of vehicle-mounted mobile radar FAR-2117 in Xiajiahe for algorithm validation, the results show that the proposed method has high accuracy in detecting sea ice concentration and the error is satisfied to meet the engineering requirement.