An image forming apparatus includes an image fixing device (9), a measuring module (101) and a control module (300). The measuring module (101) is used to measure the temperature of the image fixing device (9) to generate a temperature measure value. The control module (300) is used to control an execution mechanism to act to show that the image forming apparatus is in the working state, upon determining that the temperature measure value is lower than a preset threshold. The present invention further includes a corresponding image forming method. Advantages of the present invention are that, a user is clearly prompted that the apparatus is in a normal operation state, thereby bringing convenience to the use of the apparatus.