The invention discloses a silk weaving machine for weaving brocade patterns and its weaving method, and there is a press-obstructing mechanism in the brocade wooden machine arranged in the jacquard orifice part of ordinary silk weaving machine, the two ends of the top frame of an obstructor in the mechanism are hung on a fixed spring, and a conveyer belt connected with the two ends of the bottom frame of the obstructor is connected with vertical hooks in the heald lifting mechanism through supporting and turning wheels. It adopts a double-section single-harness mounting technique and a press-obstructing technique in the silk weaving machine to make gained plate, installs the warps, passing through ocular shield, hooks, connects, installs the press-obstructing mechanism, threads the warps, installs shutters, and starts the machine to weave. It adopts the press-obstructing technique and presses down one of the fours warps in the part with patterns, which are flat and beautiful and the pattern silks are uneasy to break, thus implementing the weaving of brocaded products in ordinary silk weaving machine.