Abstract: Hidden projects are prone to come up in renovation projects and the pre-control of them is weak. To solve this problem, a model of hidden projects quality control in renovation is constructed based on TRIZ theories. A control measure ahead of time is gained, the content of technology preparation is perfected, the probability of hidden engineering is reduced, and quality control shortage is settled. Finally, this model is applied to quality control of the Chengdu Jail Monitoring System Renovation Project.