In daily life, walking represents one of the most important biological processes, as well as the most used. When taking into account this, a person who loses a section of some lower limb presents problems or difficulties to carry out a certain process, it is for that reason, that the design of a prosthetic foot with mechanical actuator is carried out; which, taking as a starting point an analysis in a walking laboratory, in which the reaction forces of the foot with the ground, which were processed by MATLAB®, will be obtained as a starting point; likewise, through an analysis in the literature, the ideal material and actuator for the objective that is needed is sought. The implementation of the design is carried out through SolidWorks®, where through the combination of a carbon fiber structure, and the implementation of a passive actuator, such as the spring, it is possible to emulate the forces that would normally perform the muscles that were lost.