Even if the 8051 would be able to fully turn-on the BC337, then your circuit would only fabricate a gate source voltage of 4.3V, which is hardly enough to switch 10A.

Another mistake is that your scheme turns on the MOSFET, when the 8051 is emtting high level, which is no good idea, because this is the reset level.

Also, your 200V supply and the micro share the same ground. This can inject enormous interference into the microcontroller circuit during switchings. Usually this is solved by the help of a relay, which intrinsically provides a galvanic isolation between driver and load.

Kai