The invention relates to a second stage foldaway balance mechanism of a pipelayer, and a counterweight bracket is fixed with a stander together. The second stage foldaway balance mechanism of the pipelayer is provided with a first stage cantilever, a second stage cantilever, a first stage hydrocylinder and a second stage hydrocylinder, wherein, the first stage cantilever is hinged with the counterweight bracket by a first stage cantilever pin roll; the second stage cantilever is hinged with the first stage cantilever by a second stage cantilever pin roll, and each counterweight block is connected with the second stage cantilever by two counterweight pin rolls; one end of the first stage hydrocylinder is connected with the stander by a hydrocylinder pin roll, and the other end is connected with the first stage cantilever by the hydrocylinder pin roll; one end of the second stage hydrocylinder is connected with the first stage cantilever by the hydrocylinder pin roll, and the other end is connected with the second stage cantilever by the hydrocylinder pin roll; axes of all pin rolls are in vertical directions. The second stage foldaway balance mechanism of the pipelayer has compact structure, long extension distance of the counterweight, great balance moment of unit weight, and small weight of needed counterweight, thereby the weight of the complete mechanism is small, and the lift capacity of unit mechanism weight is small; a level expansion mode makes the counterweight to not need to overcome the weight of the counterweight in the process of expansion and furl, the load of the hydrocylinder is small and the cylinder diameter of the hydrocylinder is small, and the power for consuming a host is small. The performance level of the complete mechanism can be increased visibly when the second stage foldaway balance mechanism of the pipelaver is used as a balance mechanism, and the manufacturing and the transporting costs are saved.