we say spi is synchronously send and receive datas.but see this image.sending and receiving are at different clock pulses

 

In electronics synchronous means synchronised with a clock signal, not happening at the same time as something else.

 

With SPI, it is possible to be sending and receiving at the same time, and it's actually quite common. It depends on the protocol used by the particular master and slave. For example, an analog to digital converter may be sending out the results of the previous conversion on the MISO line, while receiving the next request on the MOSI line.