The utility model discloses a numerical control machining device which comprises a main shaft assembly, a U shaft assembly and a Q shaft assembly. The U shaft assembly comprises a U shaft driving mechanism and a U shaft linkage part, wherein the U shaft linkage part is connected to the U shaft driving mechanism and driven by the U shaft driving mechanism to rotate around a U shaft. The main shaft assembly is connected to the U shaft linkage part through the Q shaft assembly. The Q shaft assembly comprises a Q shaft driving mechanism for driving the main shaft assembly to linearly move along a Q shaft. The Q shaft driving mechanism is fixed on the U shaft linkage part and connected to the main shaft assembly. The Q shaft is parallel to a rotation shaft of a tool and perpendicular to the U shaft. The Q shaft assembly is used for enabling the main shaft assembly to move along the Q shaft, therefore, the distance, namely the pendulum length, between a tool point of the tool and the U shaft is adjusted to be zero, the pendulum length is not required to be measured and calculated in machining, a programmer no more depends on an operator, working efficiency of the programmer is improved, and working intensity of the operator is reduced.