The invention provides an information exchange method and system based on a cloud service, The system comprises a cloud service platform, a wireless sensor network and a client computer, and the method comprises the steps that the cloud service platform receives perception information obtained by a wireless sensor network end; The cloud service platform allocates an access permission level to thesensing information according to the importance level of the sensor node corresponding to the sensing information; The cloud service platform stores the perception information in a cloud storage partition corresponding to the access permission level of the cloud service platform; The cloud service platform receives an access request sent by a client computer, wherein the access request comprises an access permission level of the client computer and a cloud storage partition identifier requested to be accessed; And when the access permission level of the client computer exceeds the access permission level corresponding to the cloud storage partition identifier requested to be accessed, the cloud service platform sends the perception information in the corresponding cloud storage partition to the client computer.