High pressure fire resistant hydraulic fluid system is important composing part of digital electro-hydraulic control system. Oiliness of fire resistant hydraulic fluid system is contaminated or abnormality of oil pressure and oil location would influence work of system. Reasons for pollution of high pressure fire resistant hydraulic fluid and abnormality of oil pressure and oil location was analyzed. Means of faults eliminating were brought forward. This work is identified as being critical significance to promote safety of unit operation.