The invention discloses a phytoremediation system for radioactive contaminated soil remediation. The phytoremediation system consists of a reactor bracket, a phytoremediation reactor, composite contaminated soil, a humidity sensor, a super-accumulated plant, a single-chip microcomputer, a power supply, a water spraying device, a valve and a water tank. The phytoremediation reactor is filled with the composite contaminated soil; the humidity sensor is inserted in the composite contaminated soil; two ends of the single-chip microcomputer are respectively connected with the humidity sensor and the power supply; the other end of the power supply is connected with the valve; and two ends of the valve are respectively connected with the water spraying device and the water tank. The composite contaminated soil consists of a soil conditioning agent and radioactive contaminated soil, wherein the mass ratio of the soil conditioning agent to the radioactive contaminated soil is 1: 50. The phytoremediation system has the beneficial effects of low cost, simple operation and management and good effect in remediation of the radioactive contaminated soil.