A brake control apparatus for construction machinery, includes first and second brake lines through which a brake oil is supplied to a front brake device and a rear brake device of the construction machinery, first and second proportional flow control valves installed respectively in the first and second brake lines to control a flow rate of the brake oil in proportion to inputted first and second brake control signals, a sensing portion configured to detect work and travel information of the construction machinery, and a controller configured to output the first and second brake control signals in response to a brake manipulation signal of a driver, and configured to control independently the first and second proportional flow control valves based on the work and travel information of the construction machinery detected by the sensing portion.