Objective: To investigate the biomechanical factors of the lower limbs related to the mechanical energy in baseball batting skills. Methods: C3D data was collected using a motion capture system and imported into Visual 3D to establish a Hanavan multi-rigid-body human model and a rigid body model of the bat. Through a prepared pipeline command, the angular velocities and joint torques of the hip, knee, and ankle joints of the lower limbs, as well as the rotation of the trunk around the X, Y, and Z axes, were calculated and exported. A stepwise multiple linear regression analysis was performed between the independent variables and the dependent variable using SPSS, incorporating the factors and the dependent variable into the regression model. Results: The top four independent variables that have the greatest impact on the mechanical energy of the bat are as follows: x19 right ankle joint plantar flexion/dorsiflexion torque (β=91.97), x2 left ankle joint inversion/eversion torque (β=91.74), x25 right hip joint flexion/extension torque (β=91.58), and x3 left ankle joint internal rotation/external rotation torque (β=91.50). Conclusion: (1) There is a strong correlation between the right hip joint flexion/extension torque and the mechanical work of the bat. The batter generates energy transmission to the upper limbs by producing right hip joint extension torque to rotate the trunk and pelvis. (2) There is a close relationship between the adduction and abduction torque of the left ankle joint and the mechanical work of the bat, which are used for body braking in the early stage of batting and body rotation in the later stage. (3) It is necessary to conduct specific strength training for the adductors of the left ankle joint, extensors of the right hip joint, and plantar flexors of the right ankle joint to enhance batting power.