Constant-speed device for dual-steel wheel vibration road roller

The utility model relates to a constant-speed device for a dual-steel wheel vibration road roller, which comprises a speed change control handle (3) and an A/D conversion circuit (5). A constant-speed mode change-over switch (4) is additionally arranged on the control panel of the dual-steel wheel vibration road roller and is provided with two normally-closed contacts and two normally-opened contacts. The two input ends of the constant-speed mode change-over switch (4) are connected with the OUT+ end and the OUT-end of the speed change control handle (3) respectively; the two normally closed ports (b, d) of the constant-speed mode change-over switch (4) are connected with the two ends of the coil of a proportional electromagnetic valve on a variable walking pump (6) respectively, the two normally opened ports (a, c) of the constant-speed mode change-over switch (4) are connected with the 5VIN and AGND of the A/D conversion circuit (5) respectively, and the two output ports of the A/D conversion circuit (5) ar