A highly sensitive mean-reverting stochastic differential equation is a kind of widely used financial model. A Markovian switching mechanism is added into this model

and resulting in general financial model (RS CKLS for short). The purpose is to study the Euler numerical solution of RS CKLS and apply RS CKLS to study financial issues. Firstly

it is proved that there exists a unique positive global solution for a RS CKLS under appropriate conditions. Then it is shown that the Euler numerical solution of a RS CKLS converges to its real solution in the sense of probability. Finally a RS CKLS is applied to conduct empirical analysis of 7-day Shanghai interbank offered rates. Maximum likelihood method is used to estimate model parameters

and hypothesis test results show that the RS CKLS has a better performance in fitting 7-day Shanghai interbank offered rates compared with a CKLS.