The invention discloses a method and device for beam forming under pulse noise. The method comprises the steps that a target optimization problem is obtained by utilizing the sparsity of a beam forming directional diagram in combination with the minimization of the array output geometric power and l1-norm, the target optimization problem is solved by utilizing the stochastic gradient algorithm or the similar recursive least-squares method to obtain an optimal weight vector, and beam forming is carried out according to the optimal weight vector. Compared with the prior art, the target optimization problem is obtained by utilizing the sparsity of the beam forming directional diagram in combination with the minimization of the array output geometric power and l1-norm, the target optimization problem is solved by utilizing the stochastic gradient algorithm or the similar recursive least-squares method to obtain the optimal weight vector, and thus estimation of the statistical parameters of pulse noise can be avoided; the method and device for beam forming under pulse noise are applicable to almost all noise pulses; meanwhile, sidelobe jamming and noise are effectively reduced, and the output SINR is increased.