A dispensing spray pump for fluid preparation, which is arranged at a liquid storage bottle filling with the fluid preparation, comprising a piston body, a pump body, a plunger and a dispensing head, characterized in that: the piston body is fixed arranged at the bottle mouth of the liquid storage bottle through a sealed cap, the piston body comprises a first piston and a second piston with barrel-shaped, which are arranged in an identical axial direction, the first piston is located inside the second piston, the bobbin of the first piston is communication with an immersed tube, the ends of the first piston and the second piston are enclosing connected one another, a chamber with an enclosing bottom is formed between the outer wall of the first piston and the inner wall of the second piston; the pump body comprises a first pump body and a second pump body with barrel-shaped, which are arranged in an identical axial direction, the first pump body is located inside the second pump body, the first pump body and the second pump body are fixed connected one another via a radial grid, and there is a fluid channel between the outer wall of the first pump body and the inner wall of the second pump body; the first piston and the second piston are slided in the first pump body and the second pump body in a sealed manner, respectively, the first pump body is provided with a check value, a first chamber is formed between the check value and the first piston in the first pump, the check value can only open outward unidirectionally from the first chamber, the depth from the chamber mouth of the first chamber to the check value is less than the maximum stroke of the first piston, as the first piston reaches the top dead centre, it enables to lift the check value, the bobbin of the first pump body is inserted in the chamber between the second piston and the first piston, the external diameter of the first pump body is less than the inner diameter of the second piston, the second piston is slided in the fluid channel located between the first pump body and the second pump body, the chamber with an enclosing bottom is communication with the fluid channel to form a second chamber; an end of the plunger is fixed inserted in the other end of the second pump body that is corresponding to the second piston, the plunger is provided with a communicating hole that is communication with the inner and outer of the second chamber. the piston body is fixed arranged at the bottle mouth of the liquid storage bottle through a sealed cap, the piston body comprises a first piston and a second piston with barrel-shaped, which are arranged in an identical axial direction, the first piston is located inside the second piston, the bobbin of the first piston is communication with an immersed tube, the ends of the first piston and the second piston are enclosing connected one another, a chamber with an enclosing bottom is formed between the outer wall of the first piston and the inner wall of the second piston; the pump body comprises a first pump body and a second pump body with barrel-shaped, which are arranged in an identical axial direction, the first pump body is located inside the second pump body, the first pump body and the second pump body are fixed connected one another via a radial grid, and there is a fluid channel between the outer wall of the first pump body and the inner wall of the second pump body; the first piston and the second piston are slided in the first pump body and the second pump body in a sealed manner, respectively, the first pump body is provided with a check value, a first chamber is formed between the check value and the first piston in the first pump, the check value can only open outward unidirectionally from the first chamber, the depth from the chamber mouth of the first chamber to the check value is less than the maximum stroke of the first piston, as the first piston reaches the top dead centre, it enables to lift the check value, the bobbin of the first pump body is inserted in the chamber between the second piston and the first piston, the external diameter of the first pump body is less than the inner diameter of the second piston, the second piston is slided in the fluid channel located between the first pump body and the second pump body, the chamber with an enclosing bottom is communication with the fluid channel to form a second chamber; an end of the plunger is fixed inserted in the other end of the second pump body that is corresponding to the second piston, the plunger is provided with a communicating hole that is communication with the inner and outer of the second chamber.