Ion extraction from laser-induced plasma is one of the key problems in atomic vapor laser isotope separation (AVLIS) engineering. In an electrostatic field, the plasma potential is higher than both electrodes due to the plasma shield effect. And sheaths exist on both sides of the electrodes. Using numerical simulation, it has been proven that ions can be extracted by the positive electrode. In conventional ion extraction experiments using an electrostatic field, the ions are only collected at the negative electrode. We focused on the positive electrode as well as the negative collector in our experiments. The Faraday cups, fix ed on both electrodes, were used to collect the extracted ions and avoid the eff ect of power supply. As a result, the positive electrode can also extract ions. The collection ratio of positive and negative collectors decreases, as the appli ed voltage increases.