Aiming at the failure and maintenance of DT50 data collectors from CAWS600 B automatic weather stations in recent years in Shandong Province，four common faults of DT50 data collectors are classified and discussed. While repairing DT50 in a laboratory, DT50 communicates with a computer by the simplified approach, using a communication line to connect DT50 and the computer directly. The troubleshooting method of abnormal detection data failure is to replace the channel chip (CD4052). Generally, the communication failure recovery method is to replace the communication driver chip (SP312). The built in program runaway failure can be solved by rewriting the built in program. When the internal time of DT50 goes wrong, the battery in the following circuit board should be replaced by a new one. The matters needing attention in troubleshooting are also discussed. Through the four troubleshooting methods, the most failures of DT50 can be repaired successfully, except small tolerance data failure.