The application discloses an electric energy quality data collection and transmission method and system. The method comprises the following steps: signal intensity values are classified into at least three grades in advance in an ascending order: a first signal intensity section, a second signal intensity section and a third signal intensity section; a current RSSI value is obtained before transmission and then converted into a signal intensity value; the signal intensity value belongs to which signal intensity section is determined, and electric energy quality data is subjected to package transmission according to a transmission protocol based on a determination result; when the determination result is that the signal intensity value is in the first signal intensity section, the transmission size of each data package is set as N11 bytes; when the determination result is that the signal intensity value is in the second signal intensity section, the transmission size of each data package is set as N21 bytes; when the determination result is that the signal intensity value is in the third signal intensity section, the transmission size of each data package is set as N31 bytes; N11, N21 and N31 are positive integers, wherein N11