A fluid jet head with driving circuit of a heater set. A first and a second primary transistor are coupled to a first and a second heater. When the first primary transistor is turned on under control of a first control voltage and a first current is generated flowing through the first heater, the first primary transistor, and the first current path, then the first primary transistor has a first primary equivalent resistance corresponding to the first control voltage. When the second primary transistor is turned on under control of a second control voltage, and a second current is generated flowing through the second heater, the second primary transistor, and a second current path, then the second primary transistor has a second primary equivalent resistance corresponding to the second control voltage. Therefore, the thermal energy generated by the first heater is substantially equal to that generated by the second heater.