The utility model relates to a stock pretension technical field provides one kind and fixes the moment of torsion multiplier fixing device on the roofbolter with the moment of torsion multiplier. Wherein, moment of torsion multiplier fixing device includes spacing and sleeve, the sleeve with the rig protective shroud is articulated, spacing including swing arm and spacing section, the first end of swing arm with the muffjoint, second end with spacing section is connected, the swing arm can be followed the sleeve rotates and drives spacing section is rotated, spacing section is used for the counter -force arm handle cooperation with the moment of torsion multiplier, makes the moment of torsion multiplier is fixed roofbolter is last. This moment of torsion multiplier fixing device makes things convenient for the installation of moment of torsion multiplier and lifts off. In addition, its fixed?operations is simple, and loading and unloading are convenient, can reduce workman intensity of labour effectively, reduces the construction risk, saves the activity duration, improves and struts efficiency, the top plate anchor rod pretension in -process of being applied to various tunnels and chamber that can be extensive.