The invention relates to a stress and deformation field test method for a long and short pile combined retaining structure. The method comprises the following steps: (1) determining the position of atest pile section; (2) determining a combination mode of the test pile; (3) determining the length of the test pile; (4) carrying out pile body deformation and measuring the deformation; and (5) acquiring data. The method solves the problem of field test of stress and deformation of the long and short pile combined retaining structure well. The test device provided by the invention comprises a test pile, a reinforcement cage, an inclinometer, a clinometer, an embedded concrete strainometer and a data collector. The stress and deformation field test method for the long and short pile combined retaining structure provided by the invention provides an effective test means of researching the stress condition and the stress transfer mechanism of the long and short pile combined retaining structure. The test method provided by the invention can measure the internal force and displacement of the long and short pile combined retaining structure precisely to provide effective information for the long and short pile combined retaining structure design. The design method is simple and practical, and has very good application and promotional value.