The salt water injection machine can evenly inject salt water and auxiliary ingredients into meat chunks, greatly improving the grade and yield of meat products. Users can adjust the step speed, step distance, gap between meat pressing plates, and injection pressure according to process requirements to evenly, quantitatively, and continuously inject the pickling agent into the material. The equipment is equipped with an automatic needle opening function, making the needle blocking rate zero. The whole machine is made of 304 stainless steel, with a rigorous design and reasonable structure. The transmission plate is detachable, clean and hygienic, and easy to clean. It is an indispensable processing equipment for products such as ham, bacon, steak, and poultry.