The present invention relates to a catalyst used in the preparation of an acrylic acid and an acrylic acid preparation method using the same and, more specifically, disclosed are: a catalyst, which can improve the selectivity of an acrylic acid and the production yield of an acrylic acid when preparing an acrylic acid from aryl alcohol by using a heterogeneous catalyst comprising bimetallic alloycatalyst particles of gold and another metal; and an acrylic acid preparation method using the same.