At present, the research and application of preventive maintenance in the field of highway tunnel maintenance is in its infancy. To apply the advanced idea of preventive maintenance to the maintenance of operating tunnels, the preventive maintenance technology of operating highway tunnels is analyzed and defined based on mature idea of pavement preventive maintenance and the actual situation of tunnel maintenance, the benefit cost analysis method is introduced to analyze the economy of tunnel preventive maintenance, and the feasible evaluation indices and evaluation method are put forward. The economic to preventive maintenance of operating highway tunnels mainly includes the definition and calculation of tunnel maintenance costs and benefits. The maintenance costs include direct and indirect costs, and benefits include direct and indirect benefits. The calculation methods of various costs and benefits of tunnel preventive maintenance are introduced. Based on engineering economics, the economic evaluation indices of available preventive maintenance schemes are put forward, including net present value (NPV), annual cost value (AC), benefit cost ratio (RB/C) and net present value rate (NPVR), which can provide reference for decisionmaking of tunnel maintenance scheme.