Provided is a test system for hard rock breaking by a microwave intelligent loading based on true triaxial stress, including: a true triaxial stress loading device consisting of a loading frame and a rock sample moving structure; a microwave-induced hard rock breaking device consisting of an excitation cavity, a rectangular waveguide, a magnetron, a thermocouple, a circulator, a cold water circulation device, a flowmeter, a power meter, an automatic impedance tuner, a coupler, a microwave heater and a shielding cavity; and a dynamic rock response monitoring and intelligent microwave parameter control system consisting of a CCD industrial camera, a temperature acquisition device and an anti-electromagnetic high-temperature resistant acoustic wave-acoustic emission integrated sensor. According to the test system, the microwave-induced hard rock breaking test, dynamic monitoring temperature and rock breaking in microwave-induced breaking process and intelligent control over microwave power and heating time are achieved.