The invention discloses a real-time active control method for controlling surface subsidence of an expressway when a top pipe tunnel penetrates through an expressway during construction. At present, only passive monitoring is conducted on surface subsidence, however, active control is not conducted on surface subsidence, and therefore the subsidence problem cannot be solved. The real-time active control method is characterized in that a subsidence control value of the surface of the expressway is set, and a primary alarming value and a secondary alarming value are calculated according to the subsidence control value; in the jacking process of the top pipe tunnel, the subsidence amount of the surface of the expressway is collected in real time; according to the relationship of the subsidence amount, detected actually during top pipe tunnel jacking, of the expressway and the subsidence control value, the grouting position and the grouting amount are adjusted in real time through control software, the stratum is lifted, and therefore the purpose of actively controlling surface subsidence of the expressway is achieved. The real-time active control method is high in reliability, economical, practical and suitable for being used for controlling the surface subsidence of the expressway when the top pipe tunnel penetrates through the expressway during construction.