The problem of “burn-coast-burn-coast” deorbit trajectory guidance with finite thrust is studied. The entry interface conditions are transformed into indices of energy and angular momentum, based on which the critical geocentric distance of “burn-coast” deorbit problem is derived and the relationship between entry interface conditions and deorbit strategy is analyzed. Then, the relative changing law of energy and the angular momentum of spacecraft in the burn arc are derived, and the guidance equation is derived by the idea that the energy and angular momentum decrease synchronously in the same relatively rate. According to the entry interface conditions, the trajectory is supposed to be a “burn-coast-burn-coast” style. The first burn needs no guidance, and the direction of the thrust is opposite to the velocity direction. The second burn uses the guidance law. Simulations of different altitude and different entry interface conditions are implemented. The results indicate that the method can effectively solve the deorbit guidance problem that the single “burn-coast” method fails, and the computational effort is not large.