The invention relates to the technical field of construction templates, and discloses a construction template for circular culverts in an urban underground utility tunnel and a construction method of the construction template. The construction template consists of template units which are connected in a socket manner; each template unit comprises a template body, a full-length connecting piece, a horizontal reinforcing piece and a U-shaped sealing plate; the longitudinal section of each template body is U-shaped; each full-length connecting piece and the corresponding template body are staggered horizontally; each horizontal reinforcing piece is arranged at a notch of the corresponding template body; each U-shaped sealing plate is fastened with the adjacent template unit; the notch of each template body is upwards arranged in a full-length manner; each full-length connecting piece is positioned on the outer side of the notch of the corresponding template body; one end of each full-length connecting piece extends out of a tip of the corresponding template body in the axial direction of the corresponding template body; the length of each full-length connecting piece is consistent to that of the corresponding template body; a U-shaped sealing plate is arranged at the end, which is longer than the corresponding full-length connecting piece, of each template body; the longitudinal section of each U-shaped sealing plate is matched with that of the corresponding template body; each horizontal reinforcing piece is perpendicular to the axial direction of the corresponding template body; each horizontal reinforcing piece and the corresponding template body are uniformly arranged at intervals; and the end, with the corresponding U-shaped sealing plate, of each template unit and the extending end of the full-length connecting piece of the corresponding template unit are connected in a socketed manner and are fixedly welded. The construction template for circular culverts in the urban underground utility tunnel is high in strength; after being prefabricated, the template units are connected in field, construction is facilitated, and the transfer use rate is high.