The foreign secretary said he would "consider" action against China for its "serious and egregious human rights violations" against Uighur Muslims.
And he did not rule out asking Prince William, often sent on behalf of the government to attend international sporting events, not to go to the Games - due to be held in 2022.
China has been accused of oppressing and breaching the human rights of the Uighur people in Xinjiang province.
There have been widespread reports of Uighurs being held against their will in "re-education" centres, undergoing forced contraception and being subjected to a range of other restrictions.
China says the claims are "baseless" and have repeatedly denied being responsible for any mistreatment, saying the Uighurs live in "peace and harmony".
But Mr Raab said on Tuesday there was "evidence of serious and egregious human rights violations" against the minority group.
He avoided accusing the Chinese government of genocide, as the former war crimes lawyer cautioned it had to be proved that the deliberate intention was the destruction of a minority group.
Mr Raab said: "Certainly, I think the more that we see of that evidence, and I think the more the international community addresses its mind to it, the more I think we do need to look very carefully at what action we take.
"I think the concerns of what's happening to the Uighurs - the detention, the mistreatment, the forced sterilisation - is something that we can't just turn away from."
He was challenged by Tory MP Alicia Kearns to commit to boycotting the Beijing Winter Olympics.
Mr Raab did not rule it out, saying: "Generally speaking, my instinct is to separate sport from diplomacy and politics. But there comes a point where that may not be possible.
"I would say let's gather the evidence, let's work with our international partners, let's consider in the round what further action we need to take."
And asked if Prince William could be told by the government not to attend the Olympics, Mr Raab said: "That would be a corollary of the wider process of evaluating the evidence and working with our international partners and whatever further decisions we come to."
Calls for the UK to boycott the event and the International Olympic Committee to choose a new host have been supported previously by Iain Duncan Smith, an MP and former Conservative Party leader.
Prime Minister Boris Johnson weeks ago declined to say if the government would adopt that same stance.
"We will review that matter as and when we need to make a decision," he told parliament's liaison committee.
"But generally speaking, I think it is important, if you can, to protect international sporting events and, indeed, members of the royal family from political ramifications."