High voltage power transformer is widely used in all over the world as generation of electrical power in either voltage level. In power-transformer lots of equipment working together like cooling fan, Buchholz relay, breather, bushing, differential relay and so on. So it is necessary to find out problems occur in it and to eradicate them as early as possible so the high cost of High voltage power transformer does not get damage and optimum use. Here we should focus how to diminish and operate them in smarter way. In this paper an attempt has been made to elaborate the use of computer and modern automation system for protection and optimum use of High voltage power transformer, its advantages and cost effectiveness. Programmable logic controllers (PLC) can be used for control & automation of High voltage power transformer. The main reason for this is cost effectiveness and optimum use. Various functions and controls can be achieved by programming the PLC. They can be used for full plant automation including governing of auto-operation includes cooling fan, control, oil level control, automatic start/stop of pump, transformer oil leakage control, replacement of Buchholz relay by pressure sensor control, start/stop of auxiliary systems, and protection requirement etc Functions other than control like continuous monitoring, data recording, instrumentation and protections can also be performed. For remote operation, communication with PLC can be performed. For continuous monitoring purpose, a personal computer can be interfaced with PLC and continuous data can be recorded regularly.