The invention relates to a dynamic point-the-bit rotary steerable drilling tool and a measuring method thereof. The dynamic point-the-bit rotary steerable drilling tool comprises a rotary housing, a stabilized platform assembly, a hollow servo-motor assembly, a drilling fluid passage, an inner eccentric ring, an outer eccentric ring, a drilling bit shaft and a universal joint. The dynamic point-the-bit rotary steerable drilling tool also comprises a stabilized platform communication and power supply system which includes an instrument storehouse fixed at the upper end of the rotary housing, a main circuit board, an auxiliary circuit board mounted on the stabilized platform upper-end cover, an electromagnetic coupler primary-side, an electromagnetic coupler secondary winding and an electromagnetic coupler primary-side mounting plate fixed at the lower end of a coupler. The main circuit board is mounted on the electromagnetic coupler primary-side mounting plate, the electromagnetic coupler secondary winding is connected with the auxiliary circuit board, and the auxiliary circuit board is connected with the attitude sensor mounted on the side wall of the upper end of the stabilized platform body. By the dynamic point-the-bit rotary steerable drilling tool, hollow drilling fluid passage, power supply and signal transmission of the stabilized platform sensor, attitude angle parameter measurement and toolface angle real-time control of the rotary steerable drilling tool are realized.