According to the regulations of Hangzhou subway, passengers can bring small pets into the subway, but they need to meet certain conditions. Pets should be placed in pet bags or cages, and the weight should not exceed 5 kg. At the same time, pets should be kept quiet and clean in the subway, and they should not bite others or cause other adverse effects. In addition, passengers with pets need to buy a pet ticket and enter the designated carriage according to the instructions of the subway staff. Please note that the size of pet bags or cages also needs to meet the subway regulations before they can be put into the car.