The invention discloses a method for preparing a superconducting layer of a high-temperature superconducting coated conductor by depositing fluorine-free chemical solution. The method comprises the following steps of: a, preparation of precursor solution; b, the preparation of coating colloid; c, coating and drying; d, wet-type decomposition heat treatment, namely placing a substrate with a film into a tubular finance; rising the temperature to be between 100 and 150 DEG C from room temperature at the speed of 1-5DEG C/min under the protection of an argon atmosphere; introducing a mixed gas of water vapor and argon with the dew point of between 10 to 20 DEG C into the furnace to form a wet argon protective atmosphere; rising the temperature to be between 450 and 500 DEG C at the speed of 0.25 to 1.5DEG C/min; keeping the temperature for 0.5 to 2 hours; cooling to the room temperature in the argon atmosphere; and e, phase formation and heat treatment to obtain the superconducting layer. The critical current density of the superconducting layer of the high-temperature superconducting coated conductor prepared by the method is up to the same magnitude order as the that of the superconducting layer prepared by a fluorine-containing method; the superconducting layer has a high-degree biaxially texture and a flat and dense surface; and the method is easy to prepare a thicker superconducting layer and has the characteristics of low cost, simple process and suitability of large-scale industrial production.