A sewing machine of an overlock cut-and-sew type for sewing together at least two flaps (3a, 3b) of textile that are overlapping and belonging to one or more textile articles, comprising at least: - a needle plate suitable for supporting at least two overlapping flaps (3a, 3b) of textile of one or more textile articles which are sliding for forming sewing stitches (10a, 10b, 10c), the needle plate being provided with through-openings defining respective seatings for passage of sewing needles and of at least a lateral appendage defining a sliding line for the sewing stitches (10a, 10b, 10c); - a lower crochet hook; - an upper crochet hook; - an advancing device suitable for advancing said overlapping flaps (3a, 3b) of textile along an advancement direction with respect to said needle plate during a sewing operation; - a device for cutting said overlapping flaps (3a, 3b) of textile in correspondence of a cutting line of the textile, in proximity and upstream of said lateral appendage along said advancement direction of said flaps (3a, 3b) of textile; - at least a thread feeder for needles suitable for supplying sewing thread to the needles of said sewing machine; - at least a tying thread feeder for supplying tying thread to at least one from between said upper crochet and said lower crochet; - a stretcher device of the tying thread from said upper crochet and/or said lower crochet; - at least a sewing needle-bearing device; characterised in that it comprises at least three sewing needles mounted on said sewing needle-bearing device, reciprocally flanked, aligned to one another and supplied with respective sewing threads, said sewing needles being suitable for passing through said seatings of the needle plate for sewing the overlapping flaps (3a, 3b) of textile, said needle plate being provided with at least three of said seatings for passage of the sewing needles, each of said seatings for passage of the sewing needles being configured for being crossed by at least a respective sewing needle, the needle plate being provided with respective separating portions suitable for at least partially separating each seating for passage of sewing needles from the adjacent seatings for passage of needles, at least at the passage zone of the needles, such as to enable formation in parallel of at least three sewing stitches (10a, 10b, 10c) that are distinct and reciprocally distanced from one another. - a needle plate suitable for supporting at least two overlapping flaps (3a, 3b) of textile of one or more textile articles which are sliding for forming sewing stitches (10a, 10b, 10c), the needle plate being provided with through-openings defining respective seatings for passage of sewing needles and of at least a lateral appendage defining a sliding line for the sewing stitches (10a, 10b, 10c); - a lower crochet hook; - an upper crochet hook; - an advancing device suitable for advancing said overlapping flaps (3a, 3b) of textile along an advancement direction with respect to said needle plate during a sewing operation; - a device for cutting said overlapping flaps (3a, 3b) of textile in correspondence of a cutting line of the textile, in proximity and upstream of said lateral appendage along said advancement direction of said flaps (3a, 3b) of textile; - at least a thread feeder for needles suitable for supplying sewing thread to the needles of said sewing machine; - at least a tying thread feeder for supplying tying thread to at least one from between said upper crochet and said lower crochet; - a stretcher device of the tying thread from said upper crochet and/or said lower crochet; - at least a sewing needle-bearing device;