Using Unity3D, WebGL technology, OpenGL technology and 3D simulation technology, the project "Virtual Simulation Experiment of Bridge Technical Condition Assessment" was developed based on the identification of bridge engineering disease threshold control index. The application of the technology of bridge condition assessment of virtual simulation experiment teaching system, build cover experiment "preparation, implementation, review, examine the whole process of the" mix "of the implementation process, can better solve the single entity experiment because of" cost ", "security risk" and the limitation of "schedule" to "disease detection operations review, assessment, highway bridge members spatial location representation, technical condition evaluation of teaching effect is poor", Also can strengthen the student before entering the entity project site on the division of spatial position relationship between perceptual knowledge of the project, the condition of bridge engineering detection and evaluation of "normalization" operation process, realize the bridge technique condition evaluation of virtual simulation experiment "integrity, high efficiency, green, environmental protection" open and examination of full coverage of the experimental process.