A manufacturing method of an aluminum coated blank, the method comprising: arranging edges of a first coated steel sheet and a second coated steel sheet to face each other; wherein the first coated steel sheet and the second coated steel sheet are different from each other in at least one of strength and thickness, and a difference between a value from multiplication of a first strength and a first thickness of the first coated steel sheet and a value from multiplication of a second strength and a second thickness of the second coated steel sheet is less than or equal to 500 MPAx mm, bonding a joint portion that connects the first coated steel sheet to the second coated steel sheet by providing a filler wire at a boundary between the first coated steel sheet and the second coated steel sheet and applying a laser beam, wherein the filler wire includes the manganese (Mn) in an amount greater than or equal to 2.5 wt% and less than or equal to 4.0 wt% and the carbon in an amount greater than or equal to 0.5 wt% and less than or equal to 0.9%, wherein the joint portion is formed by melting the first coated steel sheet, the second coated steel sheet, and the filler wire together by applying the laser beam, each of the first coated steel sheet and the second coated steel sheet includes a base iron (12, 22) and a coated layer (14, 24) that is formed with an adhesion amount of 20 to 100 g/m 2 on at least one surface of the base iron (12, 22) and includes aluminum, and the joint portion includes aluminum (Al) in an amount greater than or equal to 0.2 wt% and less than or equal to 2.0 wt%, manganese (Mn) in an amount greater than or equal to 0.8 wt% and less than or equal to 2.5 wt%, and carbon in an amount greater than or equal to 0.1 wt% and less than or equal to 0.4 wt%, and ferrite is not formed above a highest Ac3 temperature of the first coated steel sheet and the second coated steel sheet, wherein the laser beam is applied to reciprocate across the boundary, the laser beam has a frequency of 100 to 1500 Hz, power of 1 to 20 kW, and a formation speed of the joint portion of 15 to 120 mm/sec, and a frequency and a radius of the laser beam and the formation speed of the joint portion satisfy a relationship of following Equation 1 f × r v ∝ ≥ 1, wherein, in Equation 1, α is 0.7, and f is the frequency (Hz) of the laser beam, r is the radius (mm) of the laser beam measured from a surface of the aluminum coated steel sheet, and v is the formation speed (mm/sec) of the joint portion. arranging edges of a first coated steel sheet and a second coated steel sheet to face each other; wherein the first coated steel sheet and the second coated steel sheet are different from each other in at least one of strength and thickness, and a difference between a value from multiplication of a first strength and a first thickness of the first coated steel sheet and a value from multiplication of a second strength and a second thickness of the second coated steel sheet is less than or equal to 500 MPAx mm, bonding a joint portion that connects the first coated steel sheet to the second coated steel sheet by providing a filler wire at a boundary between the first coated steel sheet and the second coated steel sheet and applying a laser beam, wherein the filler wire includes the manganese (Mn) in an amount greater than or equal to 2.5 wt% and less than or equal to 4.0 wt% and the carbon in an amount greater than or equal to 0.5 wt% and less than or equal to 0.9%, wherein the joint portion is formed by melting the first coated steel sheet, the second coated steel sheet, and the filler wire together by applying the laser beam, each of the first coated steel sheet and the second coated steel sheet includes a base iron (12, 22) and a coated layer (14, 24) that is formed with an adhesion amount of 20 to 100 g/m 2 on at least one surface of the base iron (12, 22) and includes aluminum, and the joint portion includes aluminum (Al) in an amount greater than or equal to 0.2 wt% and less than or equal to 2.0 wt%, manganese (Mn) in an amount greater than or equal to 0.8 wt% and less than or equal to 2.5 wt%, and carbon in an amount greater than or equal to 0.1 wt% and less than or equal to 0.4 wt%, and ferrite is not formed above a highest Ac3 temperature of the first coated steel sheet and the second coated steel sheet, wherein the laser beam is applied to reciprocate across the boundary, the laser beam has a frequency of 100 to 1500 Hz, power of 1 to 20 kW, and a formation speed of the joint portion of 15 to 120 mm/sec, and a frequency and a radius of the laser beam and the formation speed of the joint portion satisfy a relationship of following Equation 1 f × r v ∝ ≥ 1, wherein, in Equation 1, α is 0.7, and f is the frequency (Hz) of the laser beam, r is the radius (mm) of the laser beam measured from a surface of the aluminum coated steel sheet, and v is the formation speed (mm/sec) of the joint portion.