The invention discloses a method for detecting phosphorus and compounds thereof in the air in a working place. The method is characterized by comprising the following steps: (1) collecting the phosphorus and the compounds thereof in the air; (2) digesting the collected phosphorus and compounds; (3) adding ammonium molybdate into digested solution to generate ammonium phosphomolybdate, and regulating the PH value to be 5 to 7 by using alkaline; (4) detecting by adopting a composite modified electrode to obtain a detecting result. The detecting method disclosed by the invention is easy to operate, low in detecting cost, high in accuracy, and high in sensitivity.