Provided are a 1,3-di-substituted ketene compound having a structure as represented by formula (I) and an application thereof. Such a type of compound primarily activates peroxisome proliferator-activated receptor (PPAR) α, and also activates PPPAδ and PPPAγ. The compound may be used to treat various diseases associated with PPAR regulation and control abnormality, such as non-alcoholic fatty liver disease, and especially in treating non-alcoholic hepatitis, and may potentially be used in the treatment of diseases comprising diabetes, obesity, fibrotic diseases, cardiovascular diseases (comprising heart failure, atherosclerosis, and so on), kidney diseases (comprising chronic kidney disease, renal failure, and so on), and brain degenerative diseases (comprising Alzheimer's disease and so on), having great application value.