The invention, aiming to the limitation of a performance detection method on a battery active substance, lead powder, in lead-acid storage batteries in the prior art, discloses a lead powder electrochemical performance detection method based on a small polar plate and a test system therefor. The detection method includes the following steps: preparing a cured ripe polar plate with to-be-tested lead powder on the small polar plate; and connecting the ripe polar plate into a test system and selecting a test program. By means of the method, short-time and high-effective electrochemical detection information can be obtained. With the system, performance evaluation indices, such as charge capacity performance, cycle performance and the like, of the lead powder can be directly obtained without preparation of a battery finish product. The method is hopeful to be used for replacing a lead powder electrochemical performance detection device in which a battery finish product is required. The invention provides an effective method for researching a novel lead powder material, evaluating the electrochemical performance thereof, and evaluating the performance of the lead powder as an active substance on a polar plate of the lead-acid storage batteries.