The invention discloses an automatic spraying line of an elevator guide rail. The automatic spraying line comprises a transverse feeding machine, an upender, a longitudinal conveyor, an automatic spraying machine, a longitudinal elevator, a paint drying machine overturning discharging machine and a transverse discharging machine, which are sequentially arranged, wherein the transverse feeding machine and the transverse discharging machine are used for conveying an elevator guide rail which is placed in an inverted T shape, the longitudinal conveyor, the automatic spraying machine, the longitudinal elevator and the paint drying machine are used for conveying an elevator guide rail which is placed in an T shape, the automatic spraying machine comprises a spraying room, wherein the spraying room is communicated with a paint mist processor, a spraying stander is arranged in the spraying room, an I-shaped transmission roller is supported in the spraying stander, a first spraying mechanism and a second spraying mechanism are sequentially arranged in the spraying stander at interval, the first spraying mechanism is used for spraying a fixed arm front surface and a guide arm connecting part of the elevator guide rail, the second spraying mechanism is used for spraying a fixed arm back surface of the elevator guide rail, and the first spraying mechanism and the second spraying mechanism are also respectively communicated with a collection box through a collection funnel. The automatic spraying line has the advantage of high working efficiency.