多指令流单数据流（Multiple Instruction stream Single Datastream, MISD）是并行计算机的一种结构。MISD具有n个处理单元，按n条不同指令的要求对同一数据流及其中间结果进行不同的处理。一个处理单元的输出又作为另一个处理单元的输入。

严格意义上，采用这种结构的计算机至今没有出现，但是已经有了近似的例子。在流水线结构中，一条指令的执行过程被分为多个步骤，并且交给不同的硬件处理单元，以加快指令的执行速度。

In computing, MISD (multiple instruction, single data) is a type of parallel computing architecture where many functional units perform different operations on the same data. Pipeline architectures belong to this type, though a purist might say that the data is different after processing by each stage in the pipeline. Fault-tolerant computers executing the same instructions redundantly in order to detect and mask errors, in a manner known as task replication, may be considered to belong to this type. Not many instances of this architecture exist, as MIMD and SIMD are often more appropriate for common data parallel techniques. Specifically, they allow better scaling and use of computational resources than MISD does. However, one prominent example of MISD in computing are the Space Shuttle flight control computers.