We have no real way of knowing but this is most likely what he resembled.
Does not nature itself teach you that if a man wears long hair it is a disgrace for him,- First Corinthians 11:14
Starting with the assumption that Jesus resembled a typical peasant from 1st century Galilee, Richard Neave, a medical artist retired from the University of Manchester in England, and a team of researchers:
“… started with an Israeli skull dating back to the 1st century. They then used computer programs, clay, simulated skin and their knowledge about the Jewish people of the time to determine the shape of the face, and color of eyes and skin.”
Mike Fillon followed the research and wrote an article about the portrait in “Popular Mechanics” magazine. He said during a CNN interview that:
“There are very strong rabbinical laws in Israel that you cannot tamper with a skull or any bones, so they needed to reconstruct the skull. Using a cat scan, which is very common in hospitals, they were able to recreate the skull precisely and make a cast of it. Then they put small wooden pegs, based on anthropological data, to figure out what the muscle structure and the skin would look like, and so they layered that on using clay-like substances.”
The result is shown in the left portrait above: a person with abroad peasant’s face, dark olive skin, short curly hair and a prominent nose. His height would have been on the order of 5’ 1”; he would have weighed about 110 pounds. Alison Galloway, professor of anthropology at the University of California in Santa Cruz , said that: “This [portrait] is probably a lot closer to the truth than the work of many great masters.”
“He had no beauty or majesty to attract us to Him, nothing in His appearance that we should desire Him. He was despised and rejected by men, a man of sorrows, and familiar with suffering. Like one from whom men hide their faces He was despised, and we esteemed Him not. Surely He took up our infirmities and carried our sorrows, yet we considered Him stricken by God, smitten by Him, and afflicted. But He was pierced for our transgressions , He was crushed for our iniquities; the punishment that brought us peace was upon Him, and by His wounds we are healed.” -Isaiah 53:2-5