Causes of scorching of filter coil in switching power supply

according to the picture, it can be seen at a glance that it is the design parameters of the reactor (filter coil). Simply put, the inductance of this reactor is designed to be large, the voltage drop is large, the magnetic flux is large, the magnetic core is saturated, and the magnetic loss is too large to heat up, just the reactor itself. If the circuit really needs such a large inductance, it should replace the magnetic core made of other materials or use a larger magnetic core. In fact, the filter inductance of this simple switching power supply is not very accurate. In order not to get hot, it is enough to reduce the number of turns.