An intelligent testing method of a non-destructive testing robot in a nuclear reactor pressure vessel based on virtual reality technology, wherein the reactor pressure vessel is a nuclear power station reactor pressure vessel and the non-destructive testing robot in the method is provided with installation arms arranged to cooperate with a specific installation station in the nuclear power station reactor pressure vessel, and a pneumatic centering device is arranged at the end of each installation arm to plug with the specific installation station of the nuclear power station reactor pressure vessel; an upright post is arranged between the installation arms, and the installation arms are fixedly connected with the upright post, the lower ends of the upright post are connected with a plurality of mechanical arms for a non-destructive test; a probe tool holder is fixed at the end of each mechanical arm; wherein each mechanical arm of the non-destructive testing robot is a mechanism in which a plurality of middle linkages are connected between two terminal linkages, wherein one terminal linkage is arranged at the end of the respective mechanical arm at the lower end of the upright post, and the other terminal linkage is arranged at the other end of the respective mechanical arm, and linkages are connected with each other through a joint; the linkages from the one terminal linkage to the other terminal linkage are numbered as 0, 1, 2,..., i, the motion pair that connects an (i-1) th linkage with an i th linkage is marked as an i th joint, an i th coordinate system is established at the i th joint, a coordinate system F i defined by an origin O i and coordinate axles X i, Y i and Z i are fixedly connected to the (i-1) th linkage, wherein a non-destructive testing robot simulation model and a reactor pressure vessel simulation model are constructed through three-dimension modeling software, and the position calibration of each degree-of-freedom movement axis of the non-destructive testing robot is started by using the reactor pressure vessel as an application scenario of the three-dimension modeling software, after the non-destructive testing robot simulation model and reactor pressure vessel simulation model are initiated, the method comprises the following steps: a non-destructive testing robot for a non-destructive test is installed to a pre-set position inside the reactor pressure vessel; the position calibration of each degree-of-freedom movement axis is performed after each degree-of-freedom movement axis of the non-destructive testing robot is recovered to an initial state, and a global coordinate system for the integrity of each mechanical arm and an axle coordinate system of each degree-of-freedom movement axis are constructed; a corresponding relationship between the non-destructive testing robot simulation model and the simulated and calibrated non-destructive testing robot is established and a corresponding relationship between the reactor pressure vessel simulation model and the simulated and calibrated reactor pressure vessel is established; the non-destructive testing robot simulation model transforms the position and posture of the non-destructive testing robot simulation model in a three-dimension virtual environment on the basis of the real-time position and posture information feedback values of each degree-of-freedom movement axis of the non-destructive testing robot acquired thereby, and synchronous movement of the non-destructive testing robot is virtually displayed and controlled for a non-destructive test. a non-destructive testing robot for a non-destructive test is installed to a pre-set position inside the reactor pressure vessel; the position calibration of each degree-of-freedom movement axis is performed after each degree-of-freedom movement axis of the non-destructive testing robot is recovered to an initial state, and a global coordinate system for the integrity of each mechanical arm and an axle coordinate system of each degree-of-freedom movement axis are constructed; a corresponding relationship between the non-destructive testing robot simulation model and the simulated and calibrated non-destructive testing robot is established and a corresponding relationship between the reactor pressure vessel simulation model and the simulated and calibrated reactor pressure vessel is established; the non-destructive testing robot simulation model transforms the position and posture of the non-destructive testing robot simulation model in a three-dimension virtual environment on the basis of the real-time position and posture information feedback values of each degree-of-freedom movement axis of the non-destructive testing robot acquired thereby, and synchronous movement of the non-destructive testing robot is virtually displayed and controlled for a non-destructive test.