Abstract: Hydraulic system of vine clamping and conveying was designed in order to achieve simplification of peanut combine harvester.Working performance of hydraulic system of clamping and conveying under different speed condition was analyzed based on working characteristics of hydraulic system of peanut harvester.Results showed that pressure of hydraulic system increased sharply with vine feeding increasing，and clamping chain was blocked seriously when input flow of driving motor of system was 17 L/min.System occasionally had a high-pressure point，and clamping chain would be blocked at high-pressure point when input flow of driving motor of system was 20 L/min.Clamping chain could be operated smoothly without blocking when input flow of driving motor of system was 23 L/min.Analysis on working performance of hydraulic system could provide a theoretical basis for control method study of clamping chain speed for peanut combine harvester.