As a novel kind of focus tunable lens, dielectric elastomer actuated liquid lens has a compact structure, fast response, low cost, and outstanding tunability, which makes it attract extensive attention. Here, we present a computational model of a dielectric elastomer actuated lens with dual chambers that consist of three elastic membranes and two disconnected chambers filled with conductive and transparent liquid. The intermediate layer actuated by applied voltage deforms, changing the curvature of passive membranes and obtaining a new focal length. The simulation results calculated by the shooting method with two guessed values agree well with the experimental results. Based on this model, the effects of a set of parameters, including chamber radii, shear modulus, permittivity, prestretch ratios, and injected liquid volumes, on the tuning performance of the lens are analyzed. It is found that, by regulating the liquid volume in each chamber, both the initial focal length and the tuning range can be adjusted easily. Under the condition with specific liquid volumes, the lens possesses both positive and negative focal length during voltage actuation, indicating promoted tuning performance, which is acclaimed for optimal design.