The invention provides a portable iron roughneck positioning device. The portable iron roughneck positioning device comprises a base, a stand column fixed on the base, a lifting hydraulic cylinder arranged in the stand column, a guide cylinder arranged below the lifting hydraulic cylinder, an extension arm connected with the stand column, and an extension hydraulic cylinder connected between the extension arm and the stand column, wherein the extension arm adopts a double-parallelogram connecting rod structure or a multi-parallelogram connecting rod structure; the parallelogram connecting rods are connected through connecting plates; and a transition connecting beam is arranged at the extension end of the extension arm. The positioning device has such characteristics as high positioning precision, coherent actions, flexible operation and stable operation, and can be used for well mouth and mouse hole operations.