The invention provides a mechanical three-dimensional splitting and stretching training device. According to the mechanical three-dimensional splitting and stretching training device, a right stretching slider module is connected with a right stretching handle module through a right stretching cable module; a double-pulley fixing member is fixed inside a case module; a right splitting slider module is connected with a right splitting handle module through a right splitting cable module; a back module is mounted on the outer surface of the case module. The mechanical three-dimensional splitting and stretching training device can achieve three-dimensional splitting and stretching exercise, namely, achieving splitting and stretching simultaneously. Meanwhile, the mechanical three-dimensional splitting and stretching training device obtains a brake function and can easily keep a certain angle to obtain high exercise effectiveness.