Why my Ebike controller always broke

Hi im new to this group can i ask what is the reason why my controller always broken after a couple of minute using it? I put fuse its always broken also after that if i connect the my controller it will creat a big spark thats the time i know that my controller broke again.

What controller, what motor, what battery? Are you connecting the controller to the load before connecting the battery, as recommended?

Does your eBike controller have overheating protection? Repeated failure after 5 minutes of riding probably indicates a thermal problem.
Another possible reason could be a shorted phase winding. Take an ohm meter and measure between each pair of wires. If they differ by more than about 15%, you probably have a short in the motor.

Also, what battery, controller, and motor are you using? Without that information, diagnosing the failure will be impossible.

Im using a motor 350-500w max and my battery is 48v 20ah and my controller that i use 48v 1500w.i convert the ecoped and trasfer to kick scooter .Thank you so much for your response.

Some controllers are overrated, but any 1500W controller should stand up just fine to the task of driving an undamaged 350 watt motor.

I would recommend that you do an ohm meter test on your motor. If you do not already have one, go to the hardware store and buy a digital multimeter. I suspect that your motor is bad and is blowing controllers.

If you do not feel like getting an ohmmeter, I suggest that you open up the motor and take a look inside. If the windings are black, charred, or barbecued, your motor is toast and you need a new one.