The invention discloses an LED bulb light circuit protected by linear temperature control. The LED bulb light circuit comprises an LED driving circuit and a temperature protection circuit, wherein the LED driving circuit comprises an overcurrent and overvoltage protection unit, a rectification filtering unit, a switch constant-current unit and an output unit, the temperature protection circuit comprises a negative temperature coefficient thermistor, a reference resistor and a temperature detection and control circuit, the negative temperature coefficient thermistor is arranged on an LED light source, and the output unit is connected with a power supply unit. The LED bulb light circuit has the advantages that the negative temperature coefficient thermistor and the reference resistor are adopted, a first working temperature point is set, no any influence of the negative temperature coefficient thermistor on an LED bulb light is generated when the temperature of the LED light source is lower than the first working temperature point, a resistance value of the negative temperature coefficient thermistor changes to make current change of the LED light source linear when the temperature of the LED light source is equal to or higher than the first working temperature point, the luminous brightness of the LED lights source changes unobviously, thus, a lighting effect cannot be affected, and the LED bulb light is prevented from being overheated.