Tandem type multi-joint mechanical arm

The invention provides a tandem type multi-joint mechanical arm which comprises a mechanical arm base and three or more mechanical arm joint modules which are connected with one another in series. A pitching joint and a rotating joint are arranged in each mechanical arm joint module; the pitching joint is composed of a universal joint pin and two pitching driving devices which are arranged on the two sides of the universal joint pin in right-angled symmetric mode; each pitching driving device comprises pitching steering engines, flange rings, a speed reducing gear pair and a pitching gear pair; a driven gear of the pitching gear pair is a sector gear, and the sector gear is fixed on the universal joint pin through bolts; the rotating joint is composed of a rotating steering engine, a flange plate, a rotating gear pair, a transmission shaft and an end cover. The tandem type multi-joint mechanical arm has the advantages of being good in flexibility, accurate in locating, simple in structure, good in practicability, high in accuracy and the like.