Observed Fraunhofer spectrums are limited by achromatic performance of waveplates in solar magnetic field telescope. Comparing to the different kinds of achromatic waveplates,one which composes of five-element of polyvinyl alcohol film is chosen due to its good performance in whole scope of visible wavelength. Analyzing the measurement datum from 486.1 nm to 656.3 nm,it is found that the maximum error of retardance is in the orders of λ/350 and λ/160 for half wave plate and quarter wave plate respectively,and the maximum error of axis azimuth is in the orders of 0.2° and 0. 6° for half wave plate and quarter wave plate respectively. From the measurement data,this kind of waveplate made of polyvinyl alcohol film can be used in the whole visible spectrum,and has good performance comparing to that of birefringent crystal which is insensitive to temperature and incident angle.