A fluid machine includes a main body, two first screw rotors, two second screw rotors, a driving module, a first slide member and a second slide member. The two first screw rotors are meshingly engaged with each other. The two second screw rotors are meshingly engaged with each other. Two first screw rotors are arranged in the first chamber of the main body. Two second screw rotors are arranged in the second chamber of the main body. The driving module is arranged in the drive chamber of the main body. The first slide member can move relative to the two first screw rotors. The second slide member can move relative to the two second screw rotors. A fluid entering the main body exits after being compressed or expanded by the two first screw rotors and the two second screw rotors.