The invention provides a straight-hole-type hollow block series with vertical mortar joint mortar grooves used for a building wall body and wall body form types. The straight-hole-type hollow block series is characterized in that one wall surface or two wall surfaces of a block are equipped with vertical mortar joint mortar grooves with a depth of 10mm, one end of each vertical mortar joint mortar groove is enclosed and one end of the vertical mortar joint mortar groove is open in the block hole extension direction or in the block height; the open end of the mortar groove is up and the closed end is down during wall body construction, a single slice wall building with a clear width of 200mm can be constructed, a mixed building with a single slice wall with a clear width of 200mm as an outer wall and a single slice wall with a clear width of 100mm as a partition wall can be constructed, a composite wall building with a clear width of 300mm can be constructed, a mixed building with a composite wall with a clear width of 300mm as an outer wall and a single slice wall with a clear width of 200mm or a single slice wall with a clear width of 100mm as a partition wall can be constructed, and a mixed building with a hollow wall with a clear width of 350mm as an outer wall and a composite wall with a clear width of 300mm or a single slice wall with a clear width of 100mm as a partition wall can be constructed. As long as mantissas of a width, a depth and a floor height of a house are multiples of 100, cutting or chopping of blocks is not needed, other technical measures are not needed, and composite construction of a wall body can be achieved.