In the caisson protection engineering for a heavy punch in Changchun tractor factory, because of the former improper underground dewatering measures, the workshop wall cracking and collapsing occurred. By the serious analysis and study, a treatment plan of comprehensive treatment with dewatering, water injection, underpinning and deformation observation were made, the uneven settlement was effectively controlled with successful caisson lowering. Through the observation and comprehensive evaluation, the technology showed its good effect. The paper introduced the comprehensive treatment technology in this caisson protection engineering.