Abstract: A graded early warning system for pest quantity counting includes: at least one image capturing device used to capture images of at least one pest trapping device in an environment to generate at least one pest trapping image; at least one environment monitoring and sensing device used to detect the environment to generate at least one environment parameter; at least one pest detecting and identifying device used to detect quantities and species of multiple pests based on the at least one pest trapping image; and a cloud server used to receive the at least one pest trapping image, the at least one environment parameter, and the quantities and species of multiple pests; wherein the cloud server immediately establishes pest probability models, generates early warning signals, and prompts suppression decisions according to the at least one environment parameter and the quantities and species of multiple pests.