An electronic thermometer capable of displaying temperature by picture includes a body, a micro-controller, a display screen and a temperature-sensing element. The body has a measurement portion. The micro-controller is disposed in the body. The display screen is combined in the body. The temperature-sensing element is provided in the measurement portion and electrically connected to the micro-controller. A temperature signal sensed by the temperature-sensing element is transmitted to the micro-controller. The micro-controller converts the temperature signal into a temperature value comprising a measured integer value and a measured decimal value. The micro-controller converts the measured decimal value into a picture. The display screen is configured to display the measured integer value and the picture. The present invention further provides a method for displaying temperature measured by an electronic thermometer by picture. By displaying a picture representing the temperature, the electronic thermometer increases customer acceptance with regard to visual effect.