The invention provides a laser guiding device for puncturing tumor. The laser guiding device comprises a first laser emitter and a second laser emitter, wherein the first laser emitter is arranged atthe tail end of a first dual-freedom-degree mechanical arm; the first dual-freedom-degree mechanical arm can move along a first sliding rail; the second laser emitter is arranged at the tail end of asecond dual-freedom-degree mechanical arm; the second dual-freedom-degree mechanical arm can move along a second sliding rail; the first laser emitter and the second laser emitter transmit a horizontal laser in a backward extension line of a pre-set puncturing needle inserting point; and an intersection point of projection lines of two line lasers transmitted by the first laser emitter and the second laser emitter on the body of a patient is a puncturing needle inserting point, so that the puncturing process is guided, and precision and speed of puncturing are increased.