The invention aims to provide a round air curtain type anti-drift sprayer based on the Venturi effect. The sprayer is formed by assembling a plurality of detachable type parts designed in a split manner, and comprises a pesticide liquid conveying pipe, a loading part of the pesticide liquid conveying pipe, a pesticide liquid control pipeline, an air cavity and an air curtain type spray head. In use, airflow entering from an air cavity connection head is fast ejected out of six air flues through the air cavity, and a low pressure intensity area can be formed on the lower portion of the spray head; pesticide liquid is ejected out of a Venturi tube type spray nozzle after passing through the pesticide liquid conveying pipe and a supercharging conveying pipe; due to the Venturi tube type unique structure, the diameter of fog drops is increased, airflow ejected out of the air flues acts on fog drop groups in a high speed type, so that an effective covering area of liquid drops after being atomized is increased, and the spraying and applying precision of the sprayer and the pesticide utilizing rate are improved.