Region of interest is sliced smooth or polynomial, then accurate internal reconstruction can be performed by total variation (TV) minimization. The solution of TV minimization usually adopts the gradient descent method, taking the negative gradient of the objective function as the search direction, and then optimizes iteratively the objective function. In order to improve the efficiency of TV minimizing, this paper proposes a method to find the optimal solution direction by combining beetle antennae search (BAS) and gradient descent. The method selects the gradient descent direction or the optimal solution direction which is based on the individual “left and right whiskers” to iterate, according to the generated random number and threshold during the TV minimization process. The simulation experiment and the actual experiment show that the proposed algorithm has fast convergence speed and good reconstruction effect.