1． 目前一部分学生是通过贷款完成学业的
2． 但是有少数学生毕业后没有按时还贷款
3． 你认为有哪些原因，应该如何解决此类问题
At present,some students have been finishing their study in college by bank loans. When their at school ,they got money from banks. After graduated they have to pay the money back.
But ,the minority of the students who had finished the four years study have not paid the loans back on time.
In my opinion,they did not pay back the loans is wrong,but learning lots of graduate student experience I would argue that they just stepping into the society haven’t earned enough money to maintain their life,let alone to pay back the loans .what’s more ,the fee of tuitionis extreme expensive. So we should take measures to encourage the graduate students employ themselves and at the same time to improve the sense of credit of the graduate students.

总评：时态有问题，汉语的味道很重
At present,some students have been finishing 【have finished】their college study【studies】 by bank loans. When their 【they were in】 school ,they got 【the】 money from banks. After 【graduatation】 they 【paid】 the money back.
But ,the 【a】 minority of the students who hadfinished the【their】 four-year studies 【with bank loans】 didn't pay the loans back on time.
In my opinion, 【it is wrong】 that they did not pay back the loans. 【However】after learning the experience of many students, the fact is that they just stepped into the society and haven’t earned enough money to maintain their daily living, they don't have margin earnings to pay the loans . what’s more ,the tuition fees are extremely expensive and beyond their capability. Therefore proper measures should be taken to encourage the graduated students to employ themselves and meanwhile to improve the therir credit.