| 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 η is an any real number.Supposed thatλ1,λ2,λ3 are nonzero real numbers,not all of the same sign,withλ1/λ2 is irrational.It is proved that the inequality |λ1p1+λ2p2+λ3p3k+η|<(maxpj)σ has infinitely many solutions in prime variables p1,p2,p3,where0<σ<1/66 for k=4 and 0<σ<2k-1/(2k+1k(k+1) for k≥5. |