Abstract: The paper designed a compact, low-cost, and efficiently swimming small, single-jointed bionic robotic fish based on the propulsion mode and fin modularity of trevally fish, with easy disassembly of the pectoral, ventral, and caudal fins. In addition, the paper conducted underwater experiments on the straightline propulsion, static turning, and head stability of the bionic robotic fish, and investigated the effects of the pectoral and ventral fins on the swimming performance. In the swimming test of the prototype, the paper utilizes a high-speed camera and a plane mirror to construct a “binocular vision system” to record the movement of the fish, which can track the most anterior part of the fish head and two marking points above the prime point, and record the three-dimensional position information. This can provide a reference for quantitative analysis of swimming performance, attitude change and head stability performance. The results showed that the straight-line propulsion and turning performance of the robotic fish was better; in the stability experiment, the robotic fish equipped with pectoral and ventral fins had better head stability in low-frequency swimming, while it did not show an advantage in high-frequency swimming, which was consistent with the phenomenon that various fins except the caudal fin stick to the body in high-frequency swimming of fishes in nature.