Ecological function (E1) based on energy analysis is introduced into endoreversible four-reservoir chemical pump model. Optimization relationship between E1 and coefficient of performance (χ) is obtained. Effects of energy distribution ratio (a) of working fluid, chemical potential ratios (μH/μM and μO/μL) of material reservoirs and mass transfer coefficient ratios (b1, b2 and b3) on the optimal E1 performance are analyzed. Using NSGA-Ⅱ, taking intermediate parameter k (k=1−μ1/μH, where μ1 is chemical potentials of working fluid corresponding to reservoir μH) as optimization variable, and taking χ, dimensionless rate of energy pumping (Σ*), dimensionless E1 (E1*) and dimensionless entropy generation rate (σ*) as objective functions, multi-objective optimization (MOO) is performed, and Pareto frontiers under different optimization schemes are obtained. Deviation indices (D s) are introduced to compare the results of different MOO combinations with three decision-making methods. Trend of E1*−χ is parabolic-like one, there is an optimal χ (χE1*) to maximize E1* (E1max*); When a and μH/μM increase or μO/μL decreases, χE1* increases and E1max* decreases; When b1, b2 and b3 increase, E1max* decreases; When two-objective (σ* and E1*) optimization is carried out, the smallest D (0.3214) is obtained by TOPSIS. MOO can better balance the contradictory relationship of cycle performance parameters and improve the comprehensive performance of chemical pump.