A weighing sensor, arranged to receive a lever (2, 2') connected by means of leaf springs, characterized by comprising: a load-receiving portion, a fixing portion, and a parallel guiding portion (13, 13') connecting the load-receiving portion and the fixing portion, wherein the parallel guiding portion (13, 13') comprises an upper parallel guiding unit (131, 131') and a lower parallel guiding unit (132, 132') which are separated from each other, and two ends of the upper parallel guiding unit (131, 131') and the lower parallel guiding unit (132, 132') are respectively connected to the load-receiving portion and the fixing portion; an extension of the fixing portion, is located between the upper parallel guiding unit (131, 131') and the lower parallel guiding unit (132, 132'), is provided at a distance from both the upper parallel guiding unit (131, 131') and the lower parallel guiding unit (132, 132') and extends to the load-receiving portion, and a gap is formed between the extension of the fixing portion and the load-receiving portion; and the distance between the extension of the fixing portion and the upper parallel guiding unit (131, 131') is able to allow a lever (2, 2') to pass through and enter into a lever accommodating space formed by the fixing portion, the upper parallel guiding unit (131, 131'), and the load-receiving portion characterized in that the load-receiving portion has a protrusion extending in a direction of the fixing portion, and a through-hole is provided between the load-receiving portion and the protrusion in a direction perpendicular to the parallel guiding portion (13, 13'), wherein the protrusion is provided with a mounting region for mounting a leaf spring, and the leaf spring is provided at the mounting region by means of the through-hole. a load-receiving portion, a fixing portion, and a parallel guiding portion (13, 13') connecting the load-receiving portion and the fixing portion, wherein the parallel guiding portion (13, 13') comprises an upper parallel guiding unit (131, 131') and a lower parallel guiding unit (132, 132') which are separated from each other, and two ends of the upper parallel guiding unit (131, 131') and the lower parallel guiding unit (132, 132') are respectively connected to the load-receiving portion and the fixing portion; an extension of the fixing portion, is located between the upper parallel guiding unit (131, 131') and the lower parallel guiding unit (132, 132'), is provided at a distance from both the upper parallel guiding unit (131, 131') and the lower parallel guiding unit (132, 132') and extends to the load-receiving portion, and a gap is formed between the extension of the fixing portion and the load-receiving portion; and the distance between the extension of the fixing portion and the upper parallel guiding unit (131, 131') is able to allow a lever (2, 2') to pass through and enter into a lever accommodating space formed by the fixing portion, the upper parallel guiding unit (131, 131'), and the load-receiving portion characterized in that the load-receiving portion has a protrusion extending in a direction of the fixing portion, and a through-hole is provided between the load-receiving portion and the protrusion in a direction perpendicular to the parallel guiding portion (13, 13'), wherein the protrusion is provided with a mounting region for mounting a leaf spring, and the leaf spring is provided at the mounting region by means of the through-hole. is located between the upper parallel guiding unit (131, 131') and the lower parallel guiding unit (132, 132'), is provided at a distance from both the upper parallel guiding unit (131, 131') and the lower parallel guiding unit (132, 132') and extends to the load-receiving portion, and a gap is formed between the extension of the fixing portion and the load-receiving portion; and the distance between the extension of the fixing portion and the upper parallel guiding unit (131, 131') is able to allow a lever (2, 2') to pass through and enter into a lever accommodating space formed by the fixing portion, the upper parallel guiding unit (131, 131'), and the load-receiving portion characterized in that the load-receiving portion has a protrusion extending in a direction of the fixing portion, and a through-hole is provided between the load-receiving portion and the protrusion in a direction perpendicular to the parallel guiding portion (13, 13'), wherein the protrusion is provided with a mounting region for mounting a leaf spring, and the leaf spring is provided at the mounting region by means of the through-hole.