The cleaning process of InSb infrared detector before passivation was studied. On the basis of traditional cleaning method, a special cleaning solution was added to optimize the surface quality of InSb material before passivation. TOF-SIMS spectrometry test result showed that the Si impurity concentration on the surface of InSb material was reduced by about 85%, the concentration of main organic impurities was reduced by about 30%--60%, and the overall impurity content on the surface was significantly reduced after adding special cleaning solution. It is verified by tape-out that adding special cleaning solution for surface cleaning before passivation can improve the I-V performance and the long-term reliability of InSb photovoltaic chip significantly. This indicates that the surface quality of InSb material before passivation has an important influence on the performance and reliability of InSb infrared detectors. The optimization direction of cleaning before passivation provided in this paper has certain guiding significance.