The removable hard disk housing assembly includes a housing substrate, a hard disk supporting frame, a rotatable handle, a supporting piece, two plates-liked elements and two springs. The hard disk supporting frame is connected with the housing substrate to support a hard disk. The rotatable handle is positioned at the front side of the housing substrate. The supporting piece is rotatably positioned at the housing substrate. The plates-liked elements are movably positioned within the housing substrate and are pulled by supporting piece and protrude and retract in respond to movement of the supporting piece. Two springs are positioned between the plate-liked elements and the housing substrate and are used to bias the plate-liked elements. It prevents the hard disk from falling off when the assembly is subjected to external forces. The assembly is fixed by two extension portions so that force used to fix the assembly is well distributed.