A database access interface based on OCI9 is designed and implemented. Double conditional variable mechanism is presented in the interface to resolve the long time blocking problem caused by function when some anomalies occur in the database. Secondly, when the net wire is pulled out, the database reconnection will have a problem of the increase in memory. To avoid it, a solution of double detections of connection is put forward. Finally, experiments are made to test the application effect of the database access interface.