The invention relates to a novel crank-link mechanism which comprises a built-up crankshaft (1) and links (2), wherein the built-up crankshaft comprises a front shaft (3), a middle shaft (5), and a rear shaft (7); the left side of the middle shaft (5) is connected with front shaft (3) by a left crank arm (4); the right side of the middle shaft is connected with the rear shaft (7) by a right crank arm (6); the links (2) are arranged on the left sides and the right sides of the left crank arm (4) and the right crank arm (6) respectively; rings are arranged at the big ends and small ends of the links (2); and the cross sections of the links are I-shaped. According to the novel crank-link mechanism, the turning radiuses of the big ends of the links can be decreased effectively, so that the inner space of a crank case is reduced, and the purposes of compact design and light weight of the whole mechanism are achieved.