The invention discloses a true triaxial pressure device capable of realizing hydraulic fracturing test. A lower opening of a self-balancing pressure cylinder is sealed by a bottom cover and fixed by a bottom cover fixing part, an upper opening of the self-balancing pressure cylinder is sealed by a top cover and fixed by a top cover fixing part, a positioning part is fixed onto the bottom cover, apressure-bearing part and a test sample are arranged on the fixing parts, deformation measuring parts are arranged on the pressure-bearing part and the test sample, a hoisting ring and a high-pressure valve are arranged above the top cover, a pair of multistage self-balancing pistons and a pair of single-stage self-balancing pistons are sequentially arranged in the middle of the pressure cylinderand fixedly sealed by multistage side end covers and single-stage side end covers respectively, the multistage self-balancing pistons share a shaft, the single-stage self-balancing pistons share a shaft, and the two shafts are orthogonal on the same horizontal plane. The functions of the hydraulic fracturing test and conventional true triaxial compression test can be switched, environmental oil pressure is higher than hydraulic pressure needed by fracturing of the test sample when the hydraulic fracturing test is made, sealing is facilitated, water is prevented from being mixed into an oil way, and hydraulic cutting is realized.