In view of the large number of articles in the packaging field that require manual dispensing and painting, which is time-consuming and laborious, the paper aims to design a 3-UPS/SP parallel mechanism for dispensing and painting of packaging to improve work efficiency. The degree of freedom of the mechanism was analyzed by the spiral theory, and was verified by the modified Kutzbach-Grübler formula. Then, the closed position vector method was used to obtain the inverse position solution of the mechanism. According to the constraint conditions between the inverse position solution and the mechanism, the accessible working space of the mechanism was calculated by Matlab software programming. Finally, the application of this mechanism in dispensing and painting was analyzed through cases. The 3-UPS/SP parallel mechanism has 4 degrees of freedom which include three revolutions (rotation around the x-axis, y-axis and z-axis) and one movement (movement along the z-axis direction). It also has a large working space, and there is no ambiguity during the exercise. The mechanism has a large working space, many degrees of freedom, flexible movement, and good performance, and can be used for dispensing and painting of packaging.