An array substrate, a manufacturing method thereof and an organic light emitting diode display device are provided. The manufacturing method of the array substrate includes forming a first thin film transistor including a first semiconductor pattern, including forming a first electrode pattern including a first source electrode and a first drain electrode and a second electrode pattern including a first auxiliary source electrode and a first auxiliary drain electrode respectively through two patterning processes; forming a second thin film transistor including forming a second source electrode and a second drain electrode through one patterning process. The second electrode pattern, the second source electrode and the second drain electrode are formed in the same patterning process, the first electrode pattern is connected with the first semiconductor pattern.