Aiming at the shortcomings of the traditional solution method for multiobjective programming with independent uncertain random variables, a new method is proposed to solve the problem under the new criterion. First of all, through the introduction of uncertainty relation between random variables, an effective solution of uncertain stochastic multiobjective programming problem is defined; Then, by using sequence relationship between the variables, the uncertain stochastic multi-objective problem is transformed into single objective stochastic uncertain programming problems. The uncertain stochastic single objective programming problem is converted into a deterministic single objective programming problem via the expected-variance value principle. Then the validity is proved that the optimal solution of the deterministic single objective programming problem is an efficient solution of the original I-URMOP problem; Finally through using the improved firefly algorithm, the ISR task assignment problem of the UAV is solved, and the feasibility of the method is verified.