To obtain a shoe drive mechanism for a drum brake device capable of ensuring high effectiveness and stability of a brake at both forward/backward brake times.

As a constitution with a switch lever 32 serving as an input/ output part for a primary shoe 3 and an input lever 34 serving as an input/ output part for a secondary shoe 4 assembled capably of swiveling between a pair of base plates 25, 26 connected with a primary and a secondary anchor pin 11, 12 and a lever support pin 28, a pair of the above base plates 25, 26 are mounted turnably in a main anchor pin 10 vertically provided on a packing plate 9, by turning around the main anchor pin 10 in accordance with shoe operating force, each brake shoe 3, 4 is spread to open through each lever 32, 34 to be turned to a return side against the shoe operating force when anchor reaction force exceeds a prescribed multiplying factor.