The present invention relates to a conjugate of albumin and a temperature- and pH-sensitive multi-block copolymer, a method of preparation thereof, and a sustained-release drug carrier comprising the same, and more specifically, to a conjugate in which polyethylene glycol-poly(amino urethane) (PEG-PAU) or polyethylene glycol-poly(amino ester urethane) (PEG-PAEU) multi-block copolymer is conjugated to albumin, a method of preparing the same, and a long-term sustained-release drug carrier comprising the same, capable of reducing an initial burst release of drugs and improving an affinity to drugs.