Organic electrochemical transistors (OECTs) are useful for biochemical sensors, logic circuits, and artificial neuromorphic systems and call for insights into operation mechanisms to allow constructing complicated digital systems of high qualities. Here, we fabricate anti-freezing hydrogel based, dual-channel OECTs to probe the temperature-dependence and distance-dependence of current to investigate the ion transport. In the temperature-dependence measurement down to −30 °C, a threshold gate voltage is observed as V th , E = 0.5 V , above which the electrochemical doping mode dominates. By tuning the gate voltage above V th , E , the activation energy for hole transport is dramatically raised from 0.2 to 245.2 meV. Via the in-situ multi-point measurement, the transient response potential in neighboring channels are found not synchronous but limited by the ion transport when the ion concentration is low. The results are compared with those of OECTs based on aqueous electrolyte and reveal the operational mechanisms of OECT based on anti-freezing hydrogel. • The anti-freezing hydrogel based OECTs were fabricated to temperature-dependence measurement. • The in-situ multi-point measurement of dual-channel OECT was implemented to reveal ion transport. • The operation mode switching of OECTs was determined by the threshold gate voltage ( V th , E ). • Distance-dependence effect of ion transport was exhibited in low ionic concentration.