In Ningbo, there are only three through lanes, but there are left turn signals. I drive in the leftmost lane. Is it illegal to turn around like this?

There is a signal light when turning left, and there is no sign prohibiting turning around. It is not illegal for you to turn left at the green light. If a left turn signal light is installed, it means that the leftmost lane can go straight and turn left. If you turn left according to the signal light, there will be no problem. At the same time, there is no sign prohibiting U-turn, so U-turn is allowed. Roads in many cities are designed in this way, mainly to relieve the pressure of many through trains.