The heavy equipment airdrop mission is complex,risky and uncertain.The safety problem in the heavy equipment airdrop mission is regarded as a control problem,and it is the first time to conduct safety analysis of the heavy equipment airdrop mission based on STPA.The Unsafe Control Actions (UCA) in the heavy equipment airdrop mission are identified by system analysis,and the control feedback structure of the heavy equipment airdrop mission is established to analyze the cause of UCAs.The safety calculation framework of the heavy equipment airdrop mission is constructed,several typical UCAs are taken as the calculation analysis objects,and the quantitative safety analysis of heavy equipment airdrop is carried out.The results show that STPA can carry out safety analysis of heavy equipment airdrop effectively,and the quantitative calculation results can provide certain guidance for the crew to make scientific decisions.