The time-domain radiative transfer equation is used to simulate the propagation of pulsed laser in dispersive medium. The generalized Guess-Markov random field model is adopted to establish a regularization term and thus the ill-posed property of an inverse problem is overcome. The inverse problem is solved by the step acceleration method combined with the sequential quadratic programming algorithm. An optical imaging algorithm which does not rely on the initial values is proposed to reconstruct the distributions of absorption and scattering coefficients in the two-dimensional dispersive medium. The near-infrared optical imaging of the cancerous biological tissues is simulated. The research results show that the proposed algorithm can not only relatively well solve the initial value dependent problem, but also possesses high accuracy. The reconstructed images can show the inner structures of medium clearly.