The invention belongs to a shearing device for measuring mechanical properties of biological soft tissues. A base and a Z-axis automatic sliding table are arranged on a machine frame base plate of the device, a Z-axis driving plate is arranged on one side of the Z-axis automatic sliding table, a Z-axis sensor is arranged above the Z-axis driving plate, a carrying container is arranged on the Z-axis sensor, an X-axis automatic sliding table, a Y-axis automatic sliding table, an X-axis automatic driving guide rail and a Y-axis automatic driving guide rail are arranged on a machine frame upper plate, an X-axis driving plate and a Y-axis driving plate are arranged on the X-axis automatic sliding table and the Y-axis automatic sliding table, an X-axis sliding block, a Y-axis sliding block, an X-axis connecting plate and a Y-axis connecting plate are arranged above the X-axis automatic driving guide rail and the Y-axis automatic driving guide rail, an X-axis sensor and a Y-axis sensor are arranged between the X-axis driving plate and the Y-axis driving plate and the X-axis connecting plate and the Y-axis connecting plate, and a Y-axis driven guide rail, an X-axis driven guide rail, the X-axis sliding block and the Y-axis sliding block are arranged between the X-axis connecting plate and the Y-axis connecting plate and an upper shearing platform. The sensors, the connecting plates and the upper shearing platform are driven by the automatic sliding tables to cause deformation of a sample. Double-axial shearing is achieved by combining the upper shearing platform, side face guide rails and the sliding tables. The shearing device has the advantages of being simple in structure, good in stability, high in sensitivity, accurate in measurement and convenient to operate and carry.