The utility model provides a drifting and sand washing device which comprises an upper joint and a drift size gauge tool body. The upper joint is connected to the top of the drift size gauge tool body, a through hole is arranged at the tail end of the drift size gauge tool body, and a spiral drainage channel is arranged on the peripheral surface of the drift size gauge tool body. A pump can be switched on instantly to carry out circular sand washing and well flushing when a sand bed appears during drifting operation, the flowing direction of partial fluid can be changed via the spiral guiding drainage channel, high-speed rotational flow is formed in a casing, settled sand in a horizontal section can be effectively stirred, and sand grains are suspended, so that effects of sand washing and resistance releasing are achieved; working procedures of construction operation are reduced, the construction cycle is shortened, and the construction timeliness is improved; the drifting and sand washing device has the advantages of simple structure, convenience in processing and operation, low cost, practicality, reliability and the like; the construction cycle is shortened, the construction timeliness and the construction quality are improved, risks of settling, jamming and burying of a drilling tool due to incomplete sand washing and well flushing are avoided, and the construction safety is guaranteed; and the drifting and sand washing device is wide in application range, easy to realize large-scale popularization and utilization and broad in application prospect.