A voice wakeup detecting device for an electronic product includes a front end detecting circuit, a speech recognition processor and a main processor. The front end detecting circuit judges whether a voice signal contains a sub-keyword according to sub-keyword model parameters. If the front end detecting circuit confirms that the voice signal contains the sub-keyword, then it generates a first interrupt signal. In response to the first interrupt signal, the speech recognition processor is enabled to judge whether the voice signal contains a keyword according to keyword model parameters. If the speech recognition processor confirms that the voice signal contains the keyword, then it generates a second interrupt signal. In response to the second interrupt signal, the main processor is enabled. Consequently, the electronic produce is waked up from a sleep state to a normal working state.