Since Sodium Alginate (SA) hydrogel has disadvantages of poor controllability and low mechanical strength, it is difficult to satisfy the practical requirements when used alone. In this paper, with CaCl2 as the crosslinker, Calcium Alginate Hydrogel (CAH) was prepared as electric actuating membrane via ionic crosslinking. The non-metallic electrode membrane was fabricated from SA blended with Multi-walled Carbon Nanotube (MWCNT). Further, two electrode membranes were stuck on both sides of the actuating membrane to assemble a biodegradable Electroresponsive Biomimetic Actuator (ERBA). Moreover, an experimental platform was built for testing the output force of the ERBA cross-linked with different CaCl2 concentrations, and experimental test standards were developed according to preparation conditions and applied voltage. Then output force density was utilized to evaluate the output force characteristics. Based on in-depth analysis of the ERBA actuating mechanism, the influencing mechanisms of elastic modulus, specific capacitance and CaCl2 concentration on output force performance of the ERBA was illustrated respectively. The experimental results showed that suitable amount of the membrane solutions was 40 ml for preparing the ERBA, and its optimal test voltage was 3 V DC. When CaCl2 concentration was 0.9 g L−1, the ERBA was best cross-linked, where its elastic modulus was large and ion migration rate was fast, which caused the maximum output force density of 26.534 mN g−1. But as the CaCl2 concentration increased, the actuating membrane was cross-linked excessively, which resulted in blocked internal ion channel, small ion migration speed and reduced output force.