Abstract: Amyloidosis is a systemic disease caused by rare abnormal protein folding. Due to the non-specific clinical manifestations, this disease is prone to misdiagnosis. This article reports one case of amyloidosis predominantly complicated with gastrointestinal lesions and myocardial hypertrophy. The main clinical symptoms of the patient included chest pain, bilateral lower extremity edema, and poor appetite. Physical examination revealed macroglossia and cutaneous lesions. Electrocardiogram showed low voltage in limb leads, and cardiac ultrasound indicated myocardial thickening. Colonoscopy biopsy presented positive Congo red staining. Genetic detection identified the variant c.1253A＞G (p.Y418C) of the gelsolin (GSN) gene, and the patient was finally diagnosed with Finnish-type familial amyloidosis. This case suggests that amyloidosis can involve multiple organs with insidious clinical manifestations. Congo red staining of pathological biopsy is the gold standard for definite diagnosis. Clinicians should raise awareness of this disease and perform biopsy as early as possible to confirm the diagnosis, so as to improve the prognosis of patients.