The invention relates to an easily-extensible rule customization data monitoring method. The method comprises the following steps that a data monitoring server initializes data monitoring rules; the data monitoring server pushes the rules to a database server; a data monitoring rule scheduling mechanism is set; the database server executes monitoring rules in real time according to the set scheduling mechanism, and after the rules are executed successfully, a monitoring result is stored in a ciphertext mode; the data monitoring server extracts the monitoring result from the database server, and decoding is conducted on the monitoring result according to a secret key; summarizing and counting are conducted according to the monitoring rules. According to the easily-extensible rule customization data monitoring method, strong adaptability and expansibility to the monitoring requirements of periodic data monitoring and monitoring with non-solidifying monitoring rules are achieved, the safety and flexibility of data monitoring are enhanced, and the convenience of data monitoring is improved.