The invention provides a device for calculating the resistance of a high-order water collection cooling tower based on resistance of an air inlet and a construction method for the high-order water collection cooling tower, and aims to solve the problems that the resistance of the high-order water collection cooling tower cannot be obtained, and the high-order water collection cooling tower cannot be constructed because the conventional method for calculating the resistance of an air inlet region of the conventional cooling tower in the prior art is inapplicable to the high-order water collection cooling tower. The method comprises the following steps of: building a physical model of the high-order water collection cooling tower; measuring a water spraying area and a bottom area of a tower shell in the physical model to obtain a ratio of the water spraying area to the bottom area of the tower shell, and determining a test constant according to the ratio; determining a filling resistance coefficient through experiment; calculating the resistance of the air inlet region according to an air inlet region resistance calculation formula; calculating the resistance of the high-order water collection cooling tower according to other resistance of the cooling tower; correcting the structural size of the high-order water collection cooling tower; and constructing the high-order water collection cooling tower according to the corrected structural size. The air inlet region resistance calculation formula, the calculation device and the construction method which are suitable for the high-order water collection cooling tower are provided.