The utility model discloses a totally enclosed assembly pulley in single groove of platform truck rock drill haulage cable is strutted to hydraulic pressure, including axial region (1) and wheel portion subassembly, wheel portion subassembly includes the pulley body (2), left end lid (3), right -hand member lid (4), bearing (6) and gland (7) etc. Constitutes inclosed confined space through right side static seal circle (9), right side movable sealing ring (10), left side movable sealing ring (11) and left side static seal circle (12). The utility model has the advantages of the leakproofness is good, the fault rate is low, cost of maintenance is low and the gyration smooth and easy.