This work aims to strengthen tunnel construction, optimise construction quality, and improve the life safety of construction personnel and users under the effect that blockchain technology can improve the efficiency of information transmission and information security, and construct a blockchain-based architecture of the construction quality control system and physical architecture. On the premise of ensuring the traceability of the data, the established quality index system shall be used for intelligent evaluation of the construction quality. The test results show that: (1) when the distribution of quality status is abnormal, the probability of the quality assessment value for the qualification of steel bar quality inspection, the welding of the steel coupler and the qualification of constructors' skills all exceed 40%, which requires engineering quality diagnosis. (2) The changes in template quality assessment results under the three conditions are basically consistent with the steel bar quality. (3) The trend of concrete quality assessment results is similar to that of templates and steel bars. The main research contribution is to optimise the tunnel's construction quality control system and control the uncertain factors in the construction quality through the Bayesian network and blockchain technology and optimises the construction quality control system and construction information management.