A fixing mechanism with quick-releasing function for assembling a cover with a base includes a buckling component and an actuating component. The buckling component includes a main body, a first wedging portion, a hooking portion and a pushing portion. The first wedging portion is disposed on a hole on the main body. The hooking portion and the pushing portion are disposed on the main body and respectively protrude from the main body at different directions. The actuating component includes a shaft body and a second wedging portion. The hooking portion is engaged with a constraining portion of the base to constrain a movement between the base and the cover while the buckling component is in the first position. The pushing portion pushes the constraining portion to separate the base and the cover while the buckling component is in the second position.