A double needle sewing method enabling changeable needle distance, for implementation on a double needle sewing machine having an XY-axis feeding mechanism, a rotatable needle bar mechanism , a needle plate rotating mechanism and a needle distance adjustment mechanism , and a distance between two needles of the sewing machine being adjustable and changeable within a set distance range during the course of stitching two sewing lines , comprising: a data acquiring step , in which a plurality of pieces of stitching information presented in sequence are acquired according to two sewing lines that are to be formed on a fabric workpiece ; and each piece of the stitching information including a movement coordinate data, a rotational angle data and a needle distance data ; a stitches moving step , in which the fabric workpiece is horizontally moved by the XY-axis feeding mechanism according to those movement coordinate data sequentially; a stitches rotating step , in which a needle bar of the sewing machine is brought by the rotatable needle bar mechanism to axially rotate according to those rotational angle data sequentially, and a needle plate and a shuttle hook are brought by the needle plate rotating mechanism to rotate horizontally and synchronous with the axial rotation of the needle bar also according to those rotational angle data sequentially; and the method being characterized in that it further comprises: a needle distance changing step , in which the two needles of the sewing machine are caused by the needle distance adjustment mechanism to displace according to those needle distance data sequentially, so as to change a length of the needle distance; whereby a plurality of needle distances of different lengths are produced while the two sewing lines are continuously stitched by the two needles . a data acquiring step , in which a plurality of pieces of stitching information presented in sequence are acquired according to two sewing lines that are to be formed on a fabric workpiece ; and each piece of the stitching information including a movement coordinate data, a rotational angle data and a needle distance data ; a stitches moving step , in which the fabric workpiece is horizontally moved by the XY-axis feeding mechanism according to those movement coordinate data sequentially; a stitches rotating step , in which a needle bar of the sewing machine is brought by the rotatable needle bar mechanism to axially rotate according to those rotational angle data sequentially, and a needle plate and a shuttle hook are brought by the needle plate rotating mechanism to rotate horizontally and synchronous with the axial rotation of the needle bar also according to those rotational angle data sequentially; and the method being characterized in that it further comprises: a needle distance changing step , in which the two needles of the sewing machine are caused by the needle distance adjustment mechanism to displace according to those needle distance data sequentially, so as to change a length of the needle distance; whereby a plurality of needle distances of different lengths are produced while the two sewing lines are continuously stitched by the two needles . <EOS>