The invention discloses a concrete strain test device and a test method for a steel frame-free anchor spray-supporting tunnel. The test device comprises a positioning rod, a concrete strain gauge, a positioning buckle, a fixed pipe and a fixed base which can be installed on the surrounding rock; the fixed pipe is fixedly connected to the fixed base; the two ends of the positioning rod are respectively connected with the fixed pipe; the positioning buckle is mounted on the positioning rod; strain gauge end discs are arranged at the two ends of the concrete strain gauge; a concrete strain gaugeinterval is sleeved in the positioning buckle; and the concrete strain gauge is blocked and limited through the strain gauge end discs. The concrete strain test device can not only be prefabricated inadvance, be quickly embedded in the site to improve the working efficiency of the embedding; also, the device has a simple structure and fewer components, and has less disturbance on the original stress characteristics of the permanent anchor spray support structure. The device and the test method are used so that concrete strain distribution of the anchor spray-supporting tunnel in the form freeof steel frame support can be accurately tested.