In this paper,we mainly study the problem of Diophantine approximation with two primes and k-power of a prime.On the basis of Mu Quanwu's research,the result of the Diophantine problem is improved by using the method of enlarged major arc.The conclusions are as follows: Let k be an integer with k?4 and ? is an any real number.Supposed that?1,?2,?3 are nonzero real numbers,not all of the same sign,with?1/?2 is irrational.It is proved that the inequality |?1p1+?2p2+?3p3k+?|??maxpj?? has infinitely many solutions in prime variables p1,p2,p3,where0???1/66 for k=4 and 0???2k-1/(2k+1k?k+1? for k?5. |